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High-strength bolts. Installation of high-strength bolts shall be inspected in accordance with section 1704.3.3 of Chapter 17 of NYC Building Code and AISC 360.
Exception: Installation of high strength bolts in bearing type connections where the calculated connection strength is at least twice the required strength of the connection. Inspection of such connections shall be made under Section 1704.3.2. Such connections shall be clearly indicated on the approved construction documents.
TR1 INSPECTION ITEM: High strength bolting inspection is a required TR1 inspection item and is performed by a certified Bolting inspector. The certified bolting inspector must be certified by the International Code Council and should have a minimum of three years of work experience performing structural steel bolting inspections.
While the work is in progress, the special inspector shall determine that the requirements for bolts, nuts, washers, and paint; bolted parts and installation and tightening in such standards are met. For bolts requiring pre-tensioning, the special inspector shall observe the pre-installation testing and calibration procedures when such procedures are required by the installation method or by project plans or specifications; determine that all plies of connected materials have been drawn together and properly snugged and monitor the installation of bolts to verify that the selected procedure for installation is properly used to tighten bolts. For joints required to be tightened only to the snug-tight condition, the special inspector need only verify that the connected materials have been drawn together and properly snugged.
Periodic inspection. Inspection of bolt installation for pre-tensioning is permitted to be performed on a periodic basis when using the turn-of-nut method with match marking techniques, the direct tension indicator method, or the alternate design fastener (twist-off bolt) method. Joints designated as snug tight need to be inspected only on a periodic basis.
1704.3.3.3 Continuous inspection. Inspection of bolt installation for pre-tensioning using the calibrated wrench method or the turn-of-nut method without match marking shall be performed on a continuous basis.
High Strength Bolting Inspection Check List
Inspection Process Includes:
Verifying approved plans, procedures, specifications, standards and building codes
Verifying materials meet ASTM requirements
Verifying materials are properly stored
Verifying proper materials are used– proper bolt type, size, grade, and condition
Verifying proper fastener assemblies are utilized during bolting process
Verifying snug-tight joints prior to pre tensioning operation
Verifying fastener component not turned by wrench
Pre tensioned Fasteners in accordance to Research Council on Structural Connections (RCSC) Specification
High strength Bolting Inspection requirements as per the DOB Building Code.
HIGH STRENGTH BOLTING TORQUE CHART
The below estimated torque calculations are only offered as a guide line. Use of its content by anyone is the sole responsibility of that person and they assume all risk. Due to many variables that affect the torque-tension relationship like human error, surface texture, and lubrication the only way to determine the correct torque is through experimentation under actual joint and assembly conditions.
Use the link to find out the torque required for different type of High strength bolts.
SPECIAL INSPECTION AGENCY IN NYC AREA
ESNYC provides a full range of Special Inspections services to support our clients’ needs. This includes mechanical inspections, welding inspections, sprinkler inspections, structural inspections, as well as many other inspection types. This extensive range of inspection services has allowed us to become a single source provider to its clients throughout the life cycle of their buildings.The firm continues to evolve and expand our services throughout the New York metropolitan area. We are registered with DOB NOW.