10.008 Substitution of Specified Anchor Bolts

Q The contractor has substituted ASTM A307 Grade C anchor bolts where ASTM A36 anchor bolts are specified. Is this acceptable?

— Unknown

A 2/23/06 – Response prepared by Dave Palfini, Principal, Testing Engineers, Inc.

A quick look at the “Scope” of ASTM A307 Standard Specification for Carbon Steel Bolts and Studs, 60,000 psi Tensile Strength, indicates that Grade Cs are non-headed anchor bolts, either bent or straight, and having properties conforming to Specification A36. This seems to answer our question in a very straightforward manner

If we look at the Standard Specification ASTM A36 for Carbon Steel the mechanical properties listed in Table 3 for bars are as follows:

Tensile strength, ksi           58 – 80
Yield point, min, ksi           36
Elongation, in 2 inch, %     23

and Section 3.1of A36 states “When components of a steel structure are identified with this ASTM designation but the product form is not listed in the scope of this specification, the material shall conform to one of the standards listed in Table 1 unless otherwise specified by the purchaser.”

So, in Table 1 of A36, for anchor bolts, we find the designated specification of ASTM F1554 Standard Specification of Anchor Bolts, Steel, 36, 55, and 105-ksi Yield Strength with the following Note:

“The specifier should be satisfied of the suitability of these materials for the intended application. Composition and/or mechanical properties may be different that specified in A36/A36M.”

The mechanical property requirements for ASTM F1554 Grade 36 anchor bolts are identical to A36 and A307 Grade C.

Conclusion:   ASTM A307 designates F1554 as the controlling specification and the mechanical properties of A307 Grade C are identical to that specified for F1554 Grade 36.

Discussion:   ASTM F1554 Standard Specification of Anchor Bolts, Steel, 36, 55, and 105-ksi Yield Strength was introduced in 1999. It marked the first time that hooked, headed and threaded and nutted rods in multiple grades were fully addressed in one specification. F1554 grades 36, 55, and 105 are essentially the anchor-rod equivalent of the generic rod specification ASTM A36, A572 Grade 55, and A193 Grade B7, respectively. The benefits of F1554 are clear: there is no other specification that brings all requirements for anchor-rods together into one place – mechanical, chemical, threading, manufacturing, and dimensional. Compared to older “material-only” specifications like A36, F1554 eliminates confusion about what product is required.