In machining sliding bearing surfaces, the cut of the tool shall be in the direction of movement. In machining nonsliding bearing surfaces, the cut of the tool shall be either parallel or normal to the direction of movement.

2408.22 ABUTTING JOINTS.

A. Ends of Compression Members.
Abutting ends of compression members shall be accurately faced after the members are assembled, to secure an even bearing when assembled in the structure.

B. Ends of Tension Members.
Ends of tension members shall be neatly sheared or cut at splices with openings not exceeding 1/4 inch (6 mm).

C. Splices of Continuous Beams and Girders.
Ends of beams and girders to be spliced shall be neatly sheared or cut, with a minimum opening of 1/8 inch (3 mm) and a maximum opening not exceeding 1/4 inch (6 mm) for rolled beam spans and 1/2 inch (13 mm) for plate girder spans. This dimension shall be detailed on the shop drawings.

2408.23 END CONNECTION ANGLES.
End connection angles of floor beams and stringers shall be flush with each other and accurately set to position and length of member. In general, end connection angles shall not be machined unless indicated in the contract documents. However, faulty assembling may be cause for requiring them to be milled, in which case their thickness shall not be reduced by more than 1/16 inch (2 mm) and their bolt bearing value shall not be reduced below the design requirements.

2408.24 BORING PIN HOLES.
Pin holes shall be bored true to detailed dimensions, smooth and straight at right angles with the axis of the member and parallel with each other, unless otherwise required. A finishing cut shall always be made, and the finish shall be in accordance with Article 2408.21.

The length outside to outside of holes in tension members and inside to inside of holes in compression members shall not vary from detailed dimensions more than 1/32 inch (1 mm). Boring of holes in built up members shall be done after the bolting or welding is completed.

2408.25 PIN CLEARANCE.
The diameter of the pin hole shall not exceed that of the pin by more than 1/50 inch (0.5 mm) for pins 5 inches (125 mm) or less in diameter, or 1/32 inch (0.8 mm) for larger pins.

2408.26 FINISHED MEMBERS.
The several pieces forming one built up member shall be straight and close fitting. Finished members shall be true to detailed dimensions and free from twists, bends, open joints, or other defects resulting from faulty fabrication or defective work.

2408.27 SHOP ERECTION.
The main members of trusses, arches, continuous beam spans, bents, towers (each face), plate girders, and rigid frames shall be completely assembled for inspection in the shop when complete assembly is feasible. In lieu of complete assembly, at the option of the Contractor, progressive truss or girder assembly will be permissible, as follows:

A. Initially for each truss, arch rib, bent, tower face, or rigid frame, at least three contiguous shop sections shall be assembled, or all members in at least three contiguous panels, but not less than the number of panels associated with three contiguous chord lengths (i.e., length between field splices) and not less than 150 feet (45 m), shall be assembled in the case of structures longer than 150 feet (45 m). In order that the assembled portion of the structure is never less than that specified above, each laydown shall be composed of a sufficient number of sections or chord lengths so that the assembled portion will remain long enough when the rearward section or chord is removed after inspection of the laydown. At the option of the Contractor, the portion of the structure which is retained may be disassembled and reassembled in a new location for the new laydown.

B. Initially for each continuous beam or plate girder line, at least three contiguous shop sections shall be assembled, but in the case of structures larger than 150 feet (45 m), not less than 150 feet (45 m) of structure shall be assembled. Each succeeding laydown shall be accomplished in such a manner that at least one contiguous section shall be retained from the previous laydown and not less than 150 feet (45 m) of structure shall be assembled, except that the last laydown in a line may be less than 150 feet (45 m) long. At the option of the Contractor, the portion of the structure which is retained may be disassembled and reassembled in a new location for the new laydown.

As the shop sections are progressively assembled and removed, each retained section shall be placed in the new laydown with the same relative orientation to the erection base line as it was found to have in the previous laydown.

As the shop sections are progressively assembled and removed, suitable marks shall be scribed on the sections remaining so that accurate center to center of bearing dimensions and overall length can be achieved.

2408.28 PILOT AND DRIVING NUTS.
On pin connected spans, pilot and driving nuts shall be furnished for each size pin unless otherwise provided in the contract documents.

2408.29 MILL AND SHOP INSPECTION.
The Contractor shall give the Engineer ample notice of the beginning of work at the mill and shop so that inspection may be provided. Mill inspection of rolling will not be required unless requested by the Engineer. If inspection of rolling is not requested, the Engineer shall be furnished with complete test reports of mill inspections, showing chemical and physical tests for each heat of all structural steel sections as specified in Articles 2408.04 and 4152.02.

Material shall not be fabricated before the Engineer has been notified.

A. Inspector's Authority.
The inspector shall have the authority to reject material or work which does not fulfill the requirements of these specifications; but, in cases of dispute, the Contractor may appeal to the Engineer, whose decision shall be final.

Inspection at the mill and shop is intended as a means of facilitating the work and avoiding errors, and it is expressly understood that it will not relieve the Contractor from any responsibility in regard to imperfect material or quality of work and the necessity for replacing the same.

B. Facilities for Inspection.
Facilities for inspection shall be furnished by the Contractor for inspection of material and workmanship in the mill and shop, and inspectors shall be allowed free access to necessary parts of the premises.

C. Mill Orders and Shipping Statements.
The Contractor shall furnish the Engineer with as many copies of mill orders and shipping statements as may be requested. The weights (mass) of individual members shall be shown.

D. Rejection.
Approval of any material or finished members will not be a bar to their subsequent rejection, if found defective. Rejected material and work shall be replaced or made good by the Contractor promptly.

2408.30 SHOP PAINTING.
This specification describes surface preparation and shop painting of weathering and non-weathering structural steel and incidental parts. The work includes preparation of all surfaces to be painted, application of paint, protection, drying of paint coatings, and repairing and repainting of coating damaged in the shop and/or after erection. This specification also includes requirements for water washing of weathering structural steel.

A. Surface Preparation.
All steel surfaces to be painted shall be given a near white metal blast cleaning in accordance with SSPC-SP10. Bearing assemblies shall be cleaned of any surface contamination using suitable solvents in accordance with SSPC-SP1 and then given a near white metal blast cleaning in accordance with SSPC-SP10. SSPC-VIS 1, Visual Standard for Abrasive Blast Cleaned Steel, will be used as the standard for acceptance of the surface preparation.

Machined surfaces designated in the contract documents to have a surface roughness of ANSI 125 (3.125 µm) or less shall not be blast cleaned. Masking or other protection will be required if these parts are subjected to the blast cleaning process.

The abrasive used shall be clean, dry, and free from organic contamination. After blasting, the surface to be painted shall be thoroughly cleaned with dry, oil free, compressed air to remove all blast residue.

A sharp, angular blast profile of a minimum 1 mil (25 µm) and maximum 3 mils (75 µm) shall be achieved on all surfaces including thermal cut edges. When shot is used for blasting, the blast media shall contain at least 10% steel grit.

1. Non-weathering Structural Steel Applications.
All oily or greasy residues shall be removed with solvent in accordance with SSPC-SP1, Solvent Cleaning, before the top coat is applied. All surfaces to be top coated shall in accordance with the specification requirements and dry.

2. Weathering Structural Steel Applications.
For weathering structural steel applications, surfaces not requiring painting shall be given a Commercial Blast in accordance with specification SSPC-SP6.

To ensure uniform weathering all unpainted areas of outside surfaces of the facia girders shall receive, after blasting, at least three uniform applications of water mist at 24 hour interval between applications. Each application shall be applied on dry surfaces. The water mist application shall be performed within 48 hours after the painted surfaces have been properly cured. All water mist application shall be witnessed by a representative of the Contracting Authority.

B. Painting.
Shop painting shall be done only in a facility approved by AISC, SSPC, or the Engineer and only painters who are trained and certified by an independent outside agency for the type of work performed shall apply the paint.

The paint manufacturer's application recommendations shall be followed regarding mixing, thinning, application, pot life, steel temperature, and weather conditions. The painted areas shall have a smooth uniform, adhering coat; free of over-spray, dry spray, mud cracking, runs, sags, cracks, holidays, or other defects. Prior to painting, all surfaces shall be free of all moisture, dirt, oxidation products, oil, and other detrimental material, and shall be of a suitable temperature in accordance with the manufacturer's recommendations.

Machined surfaces with small clearances between moving components, such as full circle pins and pin holes, partial circle pins and pin recesses in castings, and similar surfaces, shall not be painted. These surfaces shall be shop coated with an application of waterproof multipurpose grease, complying with National Lubricating Grease Institute No. 3 or other approved protective coating. The protective coating shall be applied as soon as practical after component parts have been machined, welded if required, and blasted. Machined surfaces shall be thoroughly cleaned before applying the grease.

Before erection machined surfaces shall be wiped clean and given another application of grease.

1. Non-weathering Structural Steel Applications.
The prime coat and topcoat paints shall be manufactured by the same company. All painted surfaces shall be protected to prevent soiling during painting and through the tack-free stage. Care shall be taken to not damage the paint system during handling, delivery, storage, and erection of the structural steel. Damage to the prime coat attributable to shop activities shall be repaired in accordance with the paint manufacturer's recommendations before shipment to the field. Damage to the topcoat shall be repaired in accordance with manufacturer's recommendations.

All structural steel surfaces including faying surfaces of high strength bolt connections shall receive a shop applied prime coat. Also all bearing assemblies, except galvanized masonry plates and galvanized swedged bolts unless otherwise specified in the plans, shall receive a shop applied prime coat.

a. Shear Studs.
When shear studs are welded to the top of the top flange of a beam or girder after the paint system is applied, the paint shall be ground off in the areas of the weld to facilitate welding. After welding, touch-up on the top flange is not required, however, paint damage on the underside of the top flange shall be repaired.

b. Prime Coat.
All the surfaces to be painted shall be given a coat of zinc silicate paint as soon as possible after blasting before formation of any surface rust and not later than 16 hours after blasting the surface. Approved paints are shown in Materials I.M. 482.02, Appendix A. The target average dry film thickness shall be 4 mils (100 µm) with no spot measurement below 3 mils (75 µm) or above 6 mils (150 µm). Any repairs or build-up of the paint film shall be done as soon as possible and not later than 24 hours from the initial application. Steel members with coating areas measuring less than 3 mils (75 µm) that have not been corrected within 24 hours shall be completely reblasted and repainted. All defects in application such as runs, sags, mud cracking, over spray, and dry spray shall be corrected to the satisfaction of the Engineer.

Excessive coating thickness is as equally undesirable as unacceptably thin coating thickness, and both will be sufficient cause for rejection. Excessive thickness will be evaluated on a case-by-case basis in consultation with the coating manufacturer.

The inorganic zinc silicate paint film will be considered cured and ready for shipment after achieving a resistance rating of 4 as verified by 50 Methyl Ethyl Ketone (MEK) rubs as per ASTM D 4752. Moisture misting and plastic tenting maybe required during cold application temperatures and low relative humidity conditions to aid in prime coat curing.

c. Top Coat.
When designated by the contract documents, a topcoat of waterborne acrylic paint shall be shop applied to all primed surfaces. The galvanized fasteners shall be painted in accordance with Article 2408.30, B, 1, d after bolting. It is recommended that application be initiated with a mist coat applied prior to full coat application. To avoid moisture condensation, top coat shall be kept under a roof, protected from dirt, dust, and moisture, in an area where the temperature is maintained above 40°F (5°C) for a minimum 24 hours after painting is completed.

Concrete at all junction points of concrete and steel shall be shielded so that application of paint on steel is complete without over-spray on the concrete.

Approved paints are listed in Materials I.M. 482.05, Appendix A. The dry film thickness of the top coat shall be a minimum of 2 mils (50 µm). The topcoat color shall be Iowa standard foliage green Federal Color Standard Number 14223 unless otherwise specified in the contract documents.

d. Field Repair and Painting.
Paint damage due to transportation, handling, or construction activities shall be repaired and repainted by the Contractor after erection. An approved zinc rich epoxy paint, listed in Materials I.M. 482.02, Appendix C, shall be used for repair of the primer, priming un-galvanized fasteners, and any coating damage to galvanized fasteners.

Areas to be repaired and repainted shall be clean, dry, and free from grease, oil, corrosion products, and other detrimental materials. Paint shall not be applied to surfaces unless they are free from moisture or frost. The paint manufacturer's recommendations shall be followed for all aspects of repair.

When designated by the contract documents a field applied waterborne acrylic topcoat will be included.

e. Cleaning of Paint Surfaces.
Upon completion of concrete placement, exposed structural steel surfaces shall be cleaned to remove all concrete and latence before the concrete sets-up.

2. Weathering Structural Steel Applications.
All the surfaces to be painted shall be given a coat of zinc silicate paint as soon as possible after blasting before formation of any surface rust and not later than 16 hours after blasting the surface. Approved paints are shown in Materials I.M. 482.02, Appendix A. The minimum average dry film thickness shall be 4 mils (100 µm) with no spot measurement below 3 mils (75 µm) or above 6 mils (150 µm). Any repairs or build up to the applied prime coat shall be done as soon as possible and not later than 24 hours from the initial application. After the primer has cured to a resistance rating of 4 as verified by 50 MEK rubs as per ASTM D 4752 the primed surfaces shall be given a top coat of waterborne acrylic paint from the approved list shown in Materials I.M. 482.05, Appendix A. The top coat color shall match Federal Color Standard Number 20045. The top coat shall cover all the primed surfaces except faying surfaces of bolted joints with a uniform film of paint. The top coat shall be applied in the shop unless permitted in writing by the Engineer.

The following areas shall be painted:

a. All the weathering steel for a distance of 1.5 times the girder depth on each side of the expansion joints.

b. All the bearing assemblies except galvanized masonry plates and galvanized swedged bolts unless otherwise specified in the plans.

c. Embedded girder ends over the entire embedment length plus an additional distance of 1.0 foot (300 mm). The crevice between the embedded steel and concrete shall be sealed by caulking with a neutral cure and non-sag silicone. Two products meeting these criteria are Dow 888 or CSL 342 joint seal.

d. Exterior surfaces of all galvanized components which are indicated in the plans to be painted and all galvanized floor drains shall be prepared according to the written recommendations of the paint manufacturer and painted with the same type of waterborne acrylic paint used for top coat as noted in this specification.

After erection of the bridge, all fasteners in the painted areas shall be prepared using suitable hand tools, mechanical tools, or blasting equipment, and primed with a zinc rich epoxy paint from the approved list shown in Materials I.M. 482.02, Appendix C. The primed surfaces shall be cleaned and given a top coat of waterborne acrylic paint from the approved list shown in Materials I.M. 482.05, Appendix A. The color of the top coat shall match Federal Color Standard Number 20045.

Any defect or damage to the paint system after completing construction shall be prepared and repainted.

All steel surfaces shall be free of contaminants including dirt or concrete.

2408.31 MARKING AND SHIPPING.
Bolts of one length and diameter and loose nuts or washers of each size shall be packed separately. Items from different manufacturers or from different lots shall also be packaged separately. Pins, small parts, and small packages of bolts, washers, and nuts shall be shipped in boxes, crates, kegs, or barrels, but the gross weight (mass) of any package shall not exceed 300 pounds (135 kg). A list and description of the contained material shall be plainly marked on the outside of the shipping container.

2408.32 FIELD HANDLING AND STORAGE.
Loading, transportation, unloading, and piling of structural members shall be conducted so that the metal will be kept clean and free from damage by rough handling. Shipping supports, lifting devices, and deck form support points shall be padded to minimize paint damage.

All material shall be stored in a manner to prevent deterioration by rust or loss of minor parts. Material shall not be piled to rest upon the ground or in water, but must be placed on suitable skids or platforms. Girders and beams shall be placed upright and shored. Skids beneath long members, such as columns or chords, shall be close enough to prevent damaging the members by deflection.

2408.33 FALSEWORK.
Detailed plans for falsework or centering shall be supplied in accordance with Article 1105.03. In no case shall the Contractor be relieved of responsibility for results obtained by use of these plans or safety of workers on the project. Adequacy of falsework shall be subject to checking and review by the Engineer before erection of the structure which the falsework is to carry. Falsework for supporting steel during erection shall be designed to carry, without appreciable settlement or deformation, the full load coming upon it. It shall consist of either full length pile bents or framed bents supported by piles or spread footings. Bearing values of piles shall be determined as provided in Article 2501.14 and shall be at least equal to the loads imposed upon them during construction. The number and size of spread footings or mudsills used shall be determined by the load to be supported and the bearing value of the soil on which they rest, due consideration being given to the softening of soils during high water, thawing of frozen ground, etc. Mudsills shall not be used on soils or in situations where scour is likely to occur.

The safe bearing value of sand, gravel, firm clay, and other similar confined materials in beds thicker than the falsework footing width shall be considered 1,500 pounds per square foot (70 kPa).

If necessary to extend falsework above the elevation to which piles are driven, at least the majority of all piles in any bent shall be cut off at the same elevation and capped, and a framed bent shall be constructed to the required height. Each falsework bent shall be capped transversely at the proper elevation with material of adequate size securely fastened to each pile or post in the bent. All bents shall be securely braced longitudinally and transversely with diagonal bracing.

2408.34 PREPARATION OF BEARING AREA.
Column bases, truss and girder pedestals, and shoes shall have a full uniform bearing upon the concrete of the substructure. Bridge seats of piers or abutments which are improperly finished, deformed, or irregular within the bearing area of masonry plates shall be corrected before the plates are placed. Pedestals and shoes for truss and girder spans and columns for steel viaducts shall be bedded on the bearing area so as to have full and even bearing. Unless otherwise required, the bedding shall be a single layer of 1/8 inch (3 mm) sheet lead meeting requirements in Article 4195.01.

2408.35 HANDLING MEMBERS.
Component parts of a structure shall be handled by methods and appliances not likely to produce damage to the member by twisting, bending, or otherwise deforming the metal. Any member that is slightly bent or twisted shall not be put into its place until its defects are corrected. Members that have been seriously damaged in handling may be rejected.

2408.36 STRAIGHTENING BENT MATERIAL.
Straightening of plates, angles, other shapes, and built up members, when permitted by the Engineer, shall be done by methods that will not produce fracture or other injury. Distorted members shall be straightened by mechanical means, or if approved by the Engineer, by the carefully planned and supervised application of a limited amount of localized heat, except that heat straightening of ASTM A 709/A 709M Grade 100/100W (Grade 690/690W) steel members shall be done only under rigidly controlled procedures, each application subject to approval of the Engineer. In no case shall the maximum temperature of ASTM A 709/A 709M Grade 100/100W (Grade 690/690W) steel exceed 1,125°F (610°C), nor shall the temperature exceed 950°F (510°C) at the weld metal or within 6 inches (150 mm) of weld metal. Heat shall not be applied directly on weld metal. In all other steels, the temperature of the heated area shall not exceed 1,200°F (610°C) (a dull red) as controlled by use of temperature indicating crayons, liquids, or bimetal thermometers.

Parts to be heat straightened shall be substantially free of stress and from external forces, except stresses resulting from mechanical means used in conjunction with the application of heat.

Following straightening of a bend or buckle, the metal surface shall be carefully inspected for evidence of fracture. Members showing fracture shall be repaired or replaced.

2408.37 ASSEMBLING STEEL.
Parts shall be accurately assembled as shown in the contract documents and a match marking system shall be followed. Material shall be carefully handled so that parts will not be bent, broken, or otherwise damaged. Hammering which will damage or distort the members shall not be done. Bearing surfaces and surfaces to be in permanent contact shall be cleaned before the members are assembled.

Important connections in trusses, girders, floor systems, etc., shall have at least 25% of the holes on each side of the connection filled with drift pins, and another 25% of the holes on each side of the connection filled with temporary fitting up bolts drawn up snugly before the temporary support is removed. If the ultimate connection is to be made with high strength bolts, these bolts may be used as fitting up bolts. At milled connections of compression chords of truss spans, except the hip connection, the number of drift pins may be reduced to not less than 10% of the number of holes.

2408.38 ALIGNMENT.
Before placing permanent bolts in field connections, the structure shall be adjusted to correct grade and alignment. For truss spans, the elevation of each panel point (ends of floor beams) shall be blocked up on the falsework to the correct camber as shown in the contract documents and shop drawings. This blocking shall remain in place until all tension chord splices are fully bolted and all other truss connections are pinned and bolted.

Splice joints of continuous beams and girders shall be supported by adequate falsework or other approved means as directed by the Engineer, and adjusted as closely as possible to the required position before bolting is started.

2408.39 BOLTING.
Main connections shall be made with high strength bolts, nuts, and washers meeting requirements of Article 4153.06. All other fasteners will be considered non-high strength fasteners and may be used only where shown on the plans.

A. Length of Bolts.
The length of high strength bolts shall be such that, when properly installed in a snug tight condition, the end of the bolt will be flush with or outside the face of the nut.

The length of non-high strength bolts shall be such that, when tightened, there will be not less than 1/4 inch (6 mm) of bolt protruding from the nut.

The length of turned bolts shall be such that when the nut is fully threaded there will not be more than 1/8 inch (3 mm) of thread within the thickness of metal to be gripped and not more than 1/4 inch (6 mm) of thread protruding from the nut.

Ribbed bolts shall be furnished in a variety of diameters and lengths that, when installed, will result in a drive tight fit and when tightened, will fill the nut and protrude not more than 3/16 inch (5 mm).

B. Bolt Holes.
Holes for non-high strength and high strength bolts shall permit free entry of the bolt without driving. Holes for ribbed bolts shall be carefully reamed to provide for a driving fit. Holes shall be cylindrical and shall permit entry of the bolts at right angles to the faying surfaces.

C. Storage of High Strength Fasteners.
Special care shall be taken to ensure that bolts, nuts, and washers are properly protected from the elements.

D. Fastener Acceptance Testing.
Prior to steel erection the Contractor shall test, in the presence of the Engineer, two representative fastener assemblies from each rotational-capacity test lot as described in Materials I.M. 453.06B. A fastener assembly shall consist of a bolt, nut, and washer from the same rotational-city lot as furnished by the supplier. Additional rotational-capacity tests may be ordered by the Engineer if there is reason to suspect any change in fastener condition or level of lubrication. Failure of rotational-capacity tests will be cause for rejection of that fastener lot.

E. Installing High Strength Fasteners.
High strength fasteners shall be assembled, tensioned, and inspected as described below. In special cases other methods may be used with prior approval of the Engineer.

1. Assembly.
Surfaces of bolted parts adjacent to the bolt head and nuts shall be parallel. Bolted parts shall fit solidly together when assembled, without containing gaskets or any other flexible material. Holes shall not be more than 1/16 inch (2 mm) in diameter greater than the nominal bolt diameter. For slotted holes, the dimensions will be shown on the plans or shop drawings.

For painted applications, the faying surfaces shall be cleaned and primed with zinc silicate paint. For unpainted applications, faying surfaces shall be blast cleaned to remove mill scale, and be free from paint, lacquer, dirt, oil, burrs, pits, or other defects which would prevent the solid seating of parts or would interfere with the development of friction between parts.

The fastener assembly installed in the field shall be made up of bolts, nuts, and washers from the same rotational-capacity lot number. Fasteners shall be assembled with one hardened washer under the turned element (either bolt head or nut). When fasteners are specified to be galvanized, the nuts shall be furnished pre-lubricated with a dyed lubricant in accordance with ASTM A 563, or fastener threads shall be field lubricated with beeswax or other approved wax based lubricant.

For weathering structural steel, high strength weathering fasteners shall be used. For non-weathering structural steel, with or without a specified field top coat, galvanized high strength fasteners shall be used.

Each fastener, when properly tightened, shall have at least the following minimum bolt tension:

MINIMUM BOLT TENSION
Bolt Dia. inches (mm)	Min. Bolt Tension, lbf.* (kN*)	Bolt Dia. inches (mm)	Min. Bolt Tension, lbf.* (kN*)
1/2 (12.7) 5/8 (15.9) 3/4 (19.0) 7/8 (22.2) 1 (25.4)	12,050 (53.6) 19,200 (85.4) 28,400 (126.3) 39,250 (174.6) 51,500 (229.1)	1 1/8 (28.6) 1 1/4 (31.8) 1 3/8 (34.9) 1 1/2 (38.1)	56,450 (251.1) 71,700 (318.9) 85,450 (380.1) 104,000 (462.6)
* Equal to the proof load (length measurement method) given in ASTM A 325.

High strength bolts shall be tightened by the turn-of-nut method.

Impact wrenches, if used, shall be of adequate capacity and sufficiently supplied with air to develop the minimum tension of each bolt in approximately 10 seconds.

2. Turn-of-Nut Method.
The turn-of-nut method shall be used to provide the minimum bolt tension specified above.

Bolts shall be installed in all holes of the connection and brought to a "snug tight" condition. Bolts shall be considered "snug tight" when tensioned to approximately 20% of the minimum bolt tension listed above and faying surfaces are in full contact. If full contact of faying surfaces is not achieved after all bolts have been tensioned to 20% of minimum tension, the Contractor shall submit a corrective procedure to the Engineer for approval.

Snug tightening shall progress systematically from the center of the connection to the free edges. The fasteners of the connection shall be checked in similar systematic manner and retightened as necessary until all fasteners are simultaneously in a "snug tight" condition and the faying surfaces are in full and continuous contact.

When all fasteners in the connection are "snug tight", the face of the connecting part, the nut, and the bolt point shall be match-marked using paint, crayon, or other approved means to provide a reference for determining the relative rotation of the parts during final tightening.

Following this operation, all fasteners in the connection shall be tightened further by the applicable amount of rotation specified in the following table. Tightening shall progress systematically from the center of the joint to the free edges. During this operation, there shall be no rotation of the part not turned by the wrench.

NUT ROTATION FROM "SNUG TIGHT" CONDITION (*) Disposition of Outer Faces of Bolted Connections
Bolt Length (Under side of head to end of bolt)	Both Faces normal to bolt axis	One face normal to bolt axis and other slope not more than 1:20 (beveled washer not used)	Both faces sloped not more than 1:20 from normal to the bolt axis (beveled washers not used)
Up to and including 4 diameters	1/3 turn	1/2 turn	2/3 turn
Over 4 diameters but not exceeding 8 diameters	1/2 turn	2/3 turn	5/6 turn
Over 8 diameters but not exceeding 12 diameters **	2/3 turn	5/6 turn	1 turn
(*) Nut rotation shall be relative to the bolt, regardless of the element (nut or bolt) being turned. For bolts installed using 1/2 turn and less, the tolerance shall be ± 30 degrees. For bolts installed using 2/3 turn and more, the tolerance shall be ± 45 degrees.
(**) For bolt lengths exceeding 12 diameters, the required rotation must be determined by actual field tests in a suitable tension measuring device which simulates conditions of solidly fitted steel.

3. Inspection.
The Contractor shall check the bolted connections, after tightening, in the presence of the Engineer for proper installation, applicable rotation, and general joint condition. The inspection of fasteners, with a torque wrench, at connections of steel diaphragms to concrete beams will not be required.

The Contractor shall furnish and use an inspecting wrench, which shall be calibrated and capable of measuring torque.

To calibrate the inspecting wrench, a representative sample of not less than three bolts and nuts of each diameter, length, grade, and turned element, to be tensioned that day, shall be checked prior to inspection in a device capable of indicating bolt tension. The element turned during testing shall be the same element turned during actual work. The inspecting wrench shall then be used to tension the bolt and determine the torque necessary to achieve a bolt tension 5% greater than the specified minimum bolt tension. The average of the three torque values shall be the job inspecting torque value(s). The job inspecting torque value(s) shall be established at least once prior to each day's inspection. The tension measuring device shall be calibrated by an approved testing agency at least every 6 months.

Installed and tightened fasteners represented by the above tests shall be inspected for acceptance by attempting to tighten the fastener using the inspection torque wrench and the predetermined inspection torque value(s). Acceptance will be based on the random checking of at least 10% of the fasteners in each connection, with a minimum of two fasteners checked per connection. If the faying surfaces are in full and continuous contact and no bolt or nut is turned at a torque value less than or equal to the inspection torque value(s), the connection will be accepted as properly tightened.

If any bolt or nut is turned at torque values below the inspection torque value(s), all fasteners in that connection shall be checked. All bolts or nuts which turn below inspection torque values shall be tightened and reinspected.

Bolts tightened by the turn-of-nut method may reach tensions substantially above the values specified, but this shall not be cause for rejection.

4. Reuse of Bolts.
High strength bolts and nuts shall not be reused. Construction bolts or fit-up bolts shall not be incorporated into the final connection. Tensioning of fasteners up to a snug-tight condition as described in Paragraph E, 2 above, will not be considered as reuse. Retightening (touching up) previously tightened bolts which may have been loosened by the tightening of adjacent bolts will not be considered as reuse.