What are the tolerances for F1554 anchor bolts?
In our Live Chat, numerous customers have asked us about tolerances under the F1554 specification relating to things like diameter, length, straightness, and many other parameters. While a customer always has the option of specifying a particular set of tolerances they may require for any bolt, what are the default tolerances for anchor bolts under the ASTM F1554 specification? Let’s take a look.
Section 10 of the specification covers dimensional tolerances. Here is the breakdown for each dimensional tolerance that is given in the specification.
- Body Diameter (if rolled threads) – not less than the minimum pitch diameter.
- Body Diameter (if cut threads) – not less than the minimum major diameter.
- Bend Section (thickness of the steel in the area that is bent)- shall have a cross section not less than 90% of the area of straight portions.
- Length is measured from the underside of the head to the end of the threads for headed bolts or from the inside of the bend to the end of the threads for bent bolts. It is broken down into two categories of length.
- For bolts 24” or shorter the length tolerance is ± 1/2”.
- For bolts longer than 24” the length tolerance is ± 1”.
- Hook length (short leg) – ± 10% of the specified hook length, or ± 1⁄2 in., whichever is greater.
- Bend Angle—The bend angle of hooks shall not vary from that specified by more than ± 5°
- Thread Dimensions – Unless otherwise specified should be Unified Coarse Thread Series per ANSI/ASME B1.1 and have either Class 1A or 2A tolerances.
- Thread Length—+1.0 in./−0.00 in. from the length specified
This is the complete list of tolerances that are defined within the ASTM F1554 specification. If a customer desires a tolerance beyond the stated values listed above, or, if they wish to have anchor bolts meet a tolerance that is undefined in the specification, the customer would need to explicitly define the values they are requiring to the manufacturer at the time of inquiry.
What is the definition of body diameter of F1554?
@Tu-Ming- The F1554 standard allows for different values for different thread classes and threading methods. Example, for 1-8 threads, the body diameter can vary from 0.9067″ for roll threaded class 1A threads, to 0.9755″ for cut thread class 2A threads. The full chart is available in the F1554 standard.
the bolt dia 20mm bend legth 120 effective length 560 bend to 90 degree then what is full length??
@Rahul- If we are understanding you correctly, the overall length of the bolt would be 580mm. We measure from the inside, so we would call that a 20mm x 560mm x 120mm bolt.
Good Morning,
The Bolt length is 480 mm and dia is 20 mm.
The bolt got displaced by 5 to 25 mm from the original center line in certain portion of of stacker. We chipped concrete about 150 mm deep around the bolts and bend it for macing the same with original center line. Can I do it?
The bolts are projected by 130 mm from the concrete top.
@Sunil – Only F1554 Grade 36 anchor bolts should be bent in the field after installation. This FAQ provides guidelines as specified by AISC Design Guide 1.
Good Morning,
The Bolt length is 1700 mm and dia is 52 mm.
The bolt got displaced by 15 mm from the bottom most side but are in correct dimensions at top.
How to rectify.
The bolts are projected by 560 mm from the concrete.
@Shakhil – If I understand correctly, the bolt is bent? You may be able to bend it back into place. We have an FAQ on misaligned or damaged anchor bolts in the FAQ section of our website, it lays out in more detail when bending or modifying is appropriate.