Do ASTM F1554 Anchor rods have published tolerances for straightness?
ASTM F1554 specifies various dimensional tolerance ranges allowed, such as overall length and thread length, however, there are no straightness tolerances defined under the specification. This is because ASTM F1554 covers anchor bolts, which are primarily installed in concrete and rarely require straightness tolerances precise enough to where a plus or minus range would need to be defined. Since a majority of the anchor rod length is encased in concrete, it is really only the projecting threaded end that needs to be straight. One instance where straightness could be a concern is if there is an anchor template embedded in the concrete, which is common with light pole anchor bolts. In this case, there are multiple anchor rods per plate on a designated bolt circle pattern. They would then project from the concrete attaching to a base plate which has the same bolt hole pattern as the embedded template. In this case, it is important to make sure that the rods are straight enough to be able to travel through both sets of holes.
F1554 Dimensional Tolerances
Overall Bolt Length Tolerance
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+/- 1″ for lengths over
24″
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Thread Length Tolerance
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+1”, -0”
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Straightness Tolerance
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Undefined
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Can an anchor rod be manufactured to the ASTM A193 Grade B7 specification?
ASTM A193 is a specification that “covers alloy and stainless steel bolting material for pressure vessels, valves, flanges, and fittings for high temperature or high-pressure service, or other special purpose applications.” Since A193B7 is commonly available as a heavy hex bolt or fully threaded stud, it is familiar to engineers and therefore may be the grade specified for an anchor rods. This is usually due to the strength of the material. Although there isn’t anything prohibiting anchor bolts to be made to the A193 Grade B7 specification, this grade is not intended for anchor bolt use. A grade that should be considered is ASTM F1554 Grade 105. ASTM F1554 Grade 105 is a specification specifically developed for anchor bolts and possesses virtually identical chemical and physical properties.
Can ASTM A615 be used as anchor rods? They are not listed in the approved anchor bolt section of the AISC manual.
The ASTM A615 grade is a rebar specification for concrete reinforcement and makes no mention of being used as an anchor bolt in any ACI, AISC or ASTM specifications that we are aware of. Not to say that A615 rebar cannot be used as an anchor rod, however there would be some difficulties in doing this, such as the threading. The main issue is that rebar cannot simply be threaded as is due to the diameter difference between the major diameter of UNC threads and the diameter inside the deformations. There are ways around this, but often times it is recommended to consider the ASTM F1554 grade when specifying anchor rods, before considering rebar. Before ordering anchor bolts as rebar, contact us and we can discuss your requirements.
Are all of the three F1554 anchor rod grades available as hot dip galvanized?
Yes, F1554 grade 36, 55, and 105 anchor rods can all be hot dip galvanized as well as mechanically galvanized. The only time galvanizing is a risk is when the material is subject to the issue of hydrogen embrittlement, which generally only happens with grade exceeding a tensile strength of 150ksi. In Section 7 of the F1554 specification under Protective Coatings, it states that hot-dip galvanizing must be done in accordance with ASTM Specification F2329, as well as stating that mechanical galvanizing must be done in accordance with Specification B695, Class 55. It then states in Section 7.1.4 that, “When no preference is specified, the supplier may furnish either..” of these finishes at their discretion so long as the corresponding components (bolts and nuts) are coated by the same process.