Frequently Asked Questions


What is the required thread pitch for ASTM F1554 anchor bolts?

The specification states that if no thread pitch is specified, the anchor bolt should have Unified National Coarse (UNC) threads, which is the standard construction grade thread pitch, with a standard Class 2A thread dimensional tolerance.  ASTM F1554 mentions both Class 1A and Class 2A dimensional tolerances, but defaults to the standard Class 2A tolerance, if nothing is specified. ASTM F1554 does not at any point mention Unified National Fine (UNF) threads or the tight tolerance Class 3A thread dimensional requirement and thus Portland Bolt will always assume that UNC coarse threads are required unless our customer or a drawing specifies another thread pitch.

Virtually all F1554 anchor bolts are manufactured with UNC coarse threads, but on the rare occasion when 8 UN threads are required they will be specified on the plans by an engineer.  The F1554 specification does mention 8 UN threads as a potential option in diameters above 1” diameter, but in Portland Bolt’s collective experience it is exceedingly rare to see 8 UN threads on a F1554 anchor bolt being specified or required on drawings.  ASTM F1554 also does not mention metric diameters in the most recent version of the specification, but also does not prohibit metric diameters.  However, the availability of metric round bar in North America is very limited and most anchor bolt manufacturing companies in the United States are not tooled up to produce metric F1554 anchor bolts cost-efficiently.  If a metric diameter F1554 anchor bolt is specified or shows up on a drawing, the contractor should work with the Engineer of Record to determine if it is feasible to use a soft conversion to the closest Imperial size.

11. Thread Dimensions
11.1 Uncoated Anchor Bolts:
11.1.1 Unless otherwise specified, threads on Class 1A and 2A anchor bolts shall conform to Class 1A and 2A, Unified Coarse Thread Series of ASME B 1.1, respectively. When an anchor bolt class is not specified, Class 2A shall be furnished. 
11.1.2 For diameters above 1.0 in, a purchaser may specify threads conforming to Class 2A, 8 UN Thread Series of ASME B1.1.

Does F1554 cover epoxy anchor bolts?

ASTM F1554 is frequently specified and supplied as all thread rod that is embedded into an existing concrete foundation and used with epoxy. The F1554 specification does not mention epoxy or specify a type of epoxy in any way, but it is a very common application for F1554 all thread rod to be used as an epoxy anchor bolt.

Does F1554 cover wedge anchors?

No.  ASTM F1554 does not cover wedge anchor bolts or mechanical anchor bolts of any kind.  Section 1.6 of ASTM F1554 reads as follows: “This specification does not cover the requirements for mechanical expansion anchors, powder-activated nails or studs, or anchor bolts fabricated from deformed bar.”

Should I specify or use a bent anchor bolt or a headed anchor bolt/threaded rod with a nut?

Right angle bend F1554 anchor bolts are a very common configuration for a generic anchor bolt that is commonly used for light poles, substations, and other common construction applications. However, Portland Bolt has seen a shift from the predominate use of bent bolts to a very large increase in specifying headed anchor bolts or a threaded rod with a welded nut.  In fact, AISC Design Guide 1 specifically mentions that bent anchor bolts have limited pullout strength when compared to headed anchor bolts or a rod with a welded nut. Design Guide 1 goes as far as to recommend headed anchor bolts and threaded rods with a welded nut as the recommended practice for anchorage moving forward. This being said, bent anchor bolts are still very common and Portland Bolt has an extensive inventory of both bent anchor bolts and headed anchor bolts to fulfill the requests of our customers.

Does F1554 have a torque requirement?

No. There is no specified torque requirement for ASTM F1554.  In fact, there are no torque requirements for anchor bolts in general.  Per AISC Steel Construction Manual 13th Edition, the normal effort of an ironworker with a regular spud wretch is adequate to install nuts on anchor bolts.  If an anchor bolt is to be torqued to a specific torque requirement, this requirement must be specified by the engineer and the contractor must be given specific instructions.

Does F1554 allow for square head bolts or head styles other than hex or heavy hex?

The specification only mentions heavy hex or hex head bolts conforming to the dimensional requirements of B18.2.1, which is the ASME dimensional specification for hex bolts and heavy hex bolts. Portland Bolt manufactures F1554 square head anchor bolts on a regular basis, but any other head style would be unusual, but possible, and would need to be discussed before manufacturing.

Does F1554 specify if a headed anchor bolt should be a heavy hex head or a standard hex head?

F1554 does not specify a heavy hex head or hex head, but instead allows the manufacturing company to use either style at the manufacturer’s option, unless otherwise specified.

What is the pullout strength for F1554 anchor bolts?

F1554 anchor bolts have clear tensile and yield strength requirements, but calculating the final pullout strength of an anchor bolt in a concrete foundation involves a very complex amount of variables including concrete type/strength, the structure, embedment depth, anchor bolt configuration, and many other forces and issues.  Due to the complexity and liability of calculating actual pullout strength of an anchor bolt, only an engineer can make this determination on a case by case basis.

Can I weld to F1554 anchor bolts?

It depends on the grade. F1554 grade 36 is mild steel and is weldable. Grade 55 is a modified mild steel and is weldable, provided it meets the weldability requirements as described in Supplementary Requirement S1 of the F1554 specification. Grade 55 material that does not meet the S1 carbon equivalency parameters is not weldable. Grade 105 is not weldable since the heat generated during welding could alter the mechanical properties of the medium carbon alloy quenched and tempered material.

Can I galvanize F1554 anchor bolts?

All three grades of F1554 (grade 36, 55, and 105) can be galvanized. Both hot-dip galvanizing per ASTM F2329 and mechanical galvanizing per ASTM B695, class 50 are acceptable. Portland Bolt operates an in-house, state-of-the-art hot dip galvanizing line designed specifically for threaded fasteners.

My plans call for anchor bolts meeting the requirements of F1554 grade 248. I thought the three grades were 36, 55, and 105. What does 248 mean?

On some projects, engineers will designate the minimum yield strength (grade) of F1554 anchor bolt in megapascal (MPa). In this example, 248 MPa equals 36 ksi, while 380 MPa equals 55 ksi and 724 MPa equals 105 ksi.

General FAQs

Does the anchor bolt specification ASTM F1554 cover metric fasteners?

ASTM F1554 does not have any mention within the specification about metric diameters, dimensions, or options.  Many ASTM fastener specifications have metric options within the specification or even a specific grade for metric.  For instance, ASTM F3125 Grade A325 structural bolts have a metric grade called F3125 Grade A325M that covers metric diameters.  Or ASTM A563 nuts have a metric option called A563M, as do ASTM F436 washers, which is F436M.  Many other ASTM fastener specifications have grades for metric or clauses/options for metric diameters.  However, ASTM F1554 does not have any options or grades for metric diameters, but it also does not specifically prohibit metric or make mention that the specification only covers imperial diameters.

Prior to 2015, ASTM F1554 mentioned metric diameters in dimensional charts to show the rough cross conversion from imperial to metric for every diameter, but this information has now been removed from the specification, and ASTM F1554 now mentions only imperial diameters.  ASTM F1554 is the only ASTM specification for anchor bolts and does not have a metric grade or a direct metric equivalent.  Potentially the specification could be used to manufacture a metric fastener, but functionally ASTM F1554 is intended for imperial diameters.  Few, if any, US anchor bolt manufacturers are tooled up to produce metric diameter threaded fasteners and the availability of metric diameter round bar necessary to manufacture F1554 anchor bolts is uncommon.  Therefore, designers of projects requiring F1554 anchor bolts should specify imperial diameters and/or allow a soft conversion of metric to imperial dimensions on their projects.

Do headed F1554 anchor bolts need to have their forged heads stamped with the grade or manufacturers’ identification?

ASTM F1554 requires the end that projects from the concrete to be marked with a grade identification marking, which, unless otherwise specified, is blue, yellow, or red spray paint on the projecting end only. If a supplemental requirement is specified then the projecting end will be stamped with a grade stamp and/or a manufactures’ identification stamp.  The embedded end does not need to be marked in any way.  Since a headed anchor bolt functions with the forged head being embedded into concrete the head thus has no marking requirement and instead the threaded end receives spray paint or a stamp.

What happened to the ASTM A307 Grade C specification?

In August of 2007, ASTM A307 grade C was replaced by F1554 grade 36. ASTM A307 covers low carbon steel bolts and currently consists of grades A and B. Grade A covers bolts for general applications, while grade B covers heavy hex bolts and studs for cast iron flange connections. Until it was eliminated, A307 grade C covered unheaded, bent anchor bolts or straight rods. F1554 grade 36 has replaced A307 grade C and covers mild steel anchor bolts of any configuration including headed bolts.

Where can I buy a copy of the F1554 specification?

ASTM offers the complete specification on their website in hardcopy or PDF.


Does standard all thread rod that my local distributor stocks meet the requirements of F1554 grade 36?

Probably not! This question is answered in detail by following this link to Portland Bolt’s main website: F1554 Grade 36 All Thread Rod.

Can A193 grade B7 all thread rod be substituted for F1554 grade 55 all thread rod?

Absolutely not! ASTM A193 grade B7 is not an acceptable substitution since F1554 grade 55 has a maximum tensile strength requirement of 95 ksi and A193 grade B7 has a minimum tensile strength requirement of 125 ksi.

Do imported hex bolts meet the requirements of F1554 grade 36?

In most cases, mild steel hex bolts that are readily available in the marketplace will not meet the requirements of F1554 grade 36. In theory, imported A307 grade A hex bolts might meet the F1554 grade 36 requirements, but the test reports that accompany the product, if they even exist, will not verify this. The A307 grade A specification only has mechanical requirements for tensile strength (60 ksi minimum) and elongation (18% minimum). F1554 grade 36 has different requirements for tensile and elongation, in addition to having requirements for yield strength and reduction of area. Since A307 grade A does not have requirements for these additional two mechanical properties, they are typically omitted from the test reports, making it impossible to prove they meet all of the criteria without additional testing. There are very few companies besides Portland Bolt, if any, that inventory F1554 Grade 36 headed anchor bolts. Portland Bolt stocks ASTM F1554 Grade 36 hex head anchor bolts in 3/4″, 7/8″ and 1″ diameters, and will manufacture any diameter and length combination that is not in stock.

ASTM Spec Mechanical Properties
Yield, ksi, minimum Tensile, ksi Elongation, minimum Reduction of Area, minimum
A307 Grade A 60 min 18%
F1554 Grade 36 36 58 – 80 23% 40%
— indicates there is no requirement.


Is F1554 grade 55 all thread rod readily available in the marketplace?

It is virtually impossible to find stock all thread rod conforming to the requirements of F1554 grade 55. However, Portland Bolt stocks 5/8″ – 1″ diameter F1554 grade 55 all thread rod that is domestic and meets the supplemental welability requirements. Portland Bolt manufactures F1554 grade 55 all thread rod in diameters larger than 1″.

Is F1554 grade 105 all thread rod readily available in the marketplace?

It is extremely difficult to find F1554 grade 105 all thread rod in stock. Portland Bolt inventories F1554 grade 105 all thread rod from 1/2″ – 1-1/2″ diameter. All diameters above 1/2″ are 100% domestic. Larger diameter F1554 grade 105 all thread rod can be manufactured to order.