Like many special inspectors, early in my career I worked for a testing laboratory. One day I had to go out and perform High Strength Bolt Inspection and Testing. I performed the testing in the DTI device (Direct Tension Indicator - like a Skidmore) as required by the code, and was directed by the lab engineer to sample some of the bolts and send them into the lab. I asked where this requirement was at and was told to do so because they have always done this on every project. Not knowing any better, and trying not to upset anyone, I did what the lab manager told me to do. After doing this a few times I learned what the requirements of the code really was, it was not a code requirement, it never was…. aside from possibly being an AHJ (Authority Having Jursidiction - OSHPD, DSA, Local Cities and Counties, etc...) specific requirement or a specification requirement there was no reference to do this.
What is an AHJ requirement? Some projects I have been on required that any bolts which did not have "Made in the U.S.A." be sampled and destructivley tested. The City of San Diego is one AHJ that requires this and DSA has a requirement to sample a small amount of bolts which is not in line with the ASTM requirements that the manufacturer (not anyone else but the manufacturer) needs to comply with, this is just something as an AHJ they are allowed to mandate. Keep in mind if the project requires someone to sample and destructivley test bolts in a lab, then it needs to be spelled out in the "Approved Construction Documents" which is the plans and specs (for DSA this includes the T&I sheet and OSHPD is the TIO program, both of which come with the approved building permit) because this is above and beyond the basic code requirements for identifiable HSB (High strength bolts).
So what are the basic code requirements?
CBC Section 2212A Testing
2212A.1 Tests of high-strength bolts, nuts and washers.
High-strength bolts, nuts and washers shall be sampled and tested by an approved independent testing laboratory for conformance with the requirements of Section 2205A.
Unfortunately Section 2205A does not say anything about High Strength Bolting, but it does say the following:
2205A.l General.The design, fabrication and erection of structural steel for buildings and structures shall be in accordance with AISC 360.
Section 2204A.2 states the following:
Bolting. The design, installation and inspection of bolts shall be in accordance with the requirements of the specifications listed in Sections 220SA, 2206A, 2209A and 2210A.
Special inspection of the installation of high-strength bolts shall be provided where required by Section 1704.
Chapter 35 Referenced Standards lists the following:
AISC 360-2005 Specification for Structural Steel Buildings .............. 1604.3.3, Table 1704.3, 1704.3.3,2203.1,2203.2,2205.1,2205.3
Out of all of these references, only Table 1704.3/1704A.3 talks about high-strength bolts.
1. Material verification of high-strength bolts, nuts and washers:
a. Identification markings to conform to ASTM standards specified in the approved construction documents.
i. AISC 360, Section A3.3 and applicable ASTM Material Standards
b. Manufacturer's certificate of compliance required.
AISC 360 Section A3.3 3.
3. Bolts, Washers and Nuts
Bolt, washer, and nut material conforming to one of the following ASTM specifications is approved for use under this Specification:
(4) Compressible-Washer-Type Direct Tension Indicators:
Manufacturer’s certification shall constitute sufficient evidence of conformity with the standards.
This part of the code needs to be remphasised:
"Manufacturer’s certification shall constitute sufficient evidence of conformity with the standards."
AISC 360-2005 Section A3.3 Bolts, Washers and Nuts
The ASTM standard specification for A307 bolts covers two grades of fasteners. Either grade may be used under this Specification; however, it should be noted that Grade B is intended for pipe flange bolting and Grade A is the grade long in use for structural applications.
1704A.3.3 High-strength bolts. Installation of high strength bolts shall be inspected in accordance with AISC 360.
Appendix 5 Evaluation of Existing Structures
Section 5.2.6 6. Bolts and Rivets
Representative samples of bolts shall be inspected to determine markings and classifications. Where bolts cannot be properly identified visually, representative samples shall be removed and tested to determine tensile strength in accordance with ASTM F606 or ASTM F606M and the bolt classified accordingly. Alternatively, the assumption that the bolts are ASTM A307 shall be permitted.
6. Bolts and Rivets
Because connections typically are more reliable than structural members, removal and strength testing of fasteners is not usually necessary. However, strength testing of bolts is required where they cannot be properly identified otherwise.
I have spoken with many of the larger labs in the state as well as several larger fabricators. After sampling over 3,000,000 bolts, only 2 bolts have ever failed, this was due to the A490 bolts ended up being too strong. This is a pretty good record in any industry.
Some people say safety first, well I agree with that but we do not wear helmets and seatbelts while we drive our car… safety-first right. Bottom line is this, some things are overkill, some things are not code, and some things are performed just because nobody asks why are we doing this. In this case, sampling bolts and sending them into a lab when they are identified properly with material certifications and all other documentation in line are just an extra cost to the owner and delay projects. Unless the AHJ requires you to take samples and break them in the lab or the project specifications tell you to do so specifically, do the right thing and ask the question, why is someone telling me to do this? Sampling and breaking bolts does not benefit anyone, except for the one breaking the bolts. There is at least a .0000006% chance that a HSB will fail (2/3,000,000).