Technically reviewed by Vincent, Founder at HEXVARO
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Quick answer
Quick answer: F1554 Grade 36 vs 55 vs 105
Minimum yield, tensile range, end colour code and diameter range for each grade, read from the full comparison table below. The structural engineer selects the grade for the connection.
| Grade | Yield strength, min | Tensile strength | End colour code | Diameter range |
|---|---|---|---|---|
| Grade 36 | 36 ksi (248 MPa) | 58–80 ksi | Blue | 1/2 to 4 in |
| Grade 55 | 55 ksi (380 MPa) | 75–95 ksi | Yellow | 1/2 to 4 in |
| Grade 105 | 105 ksi (724 MPa) | 125–150 ksi | Red | 1/2 to 3 in |
F1554 grade comparison
The colour is painted on the end of the rod that projects above the concrete so inspectors can check the grade on site. If the grade is stamped on the end under supplementary requirement S3, painting is not required.
| Property | Grade 36 | Grade 55 | Grade 105 |
|---|---|---|---|
| Yield strength, min | 36 ksi (248 MPa) | 55 ksi (380 MPa) | 105 ksi (724 MPa) |
| Tensile strength | 58–80 ksi | 75–95 ksi | 125–150 ksi |
| Elongation, min | 23% | 21% | 15% |
| Reduction of area, min | 40% | 30% | 45% |
| End colour code | Blue | Yellow | Red |
| Diameter range | 1/2 to 4 in | 1/2 to 4 in | 1/2 to 3 in |
| Steel | Low-carbon, mild steel | Low-alloy or carbon steel | Alloy steel, quenched and tempered |
Weldability and the S1 supplement
Grade 36 is generally weldable. Grade 55 is weldable only when supplement S1 is specified; S1 limits the chemistry and sets a carbon-equivalent formula. Without S1, a Grade 55 rod may or may not be weldable. Grade 105 is a quenched-and-tempered alloy and is not intended to be welded.
If anchor rods will be welded to base plates, embedded plates or rebar, write "F1554 Grade 55 S1" or "F1554 Grade 36" in the RFQ. When Grade 36 is specified, the standard allows a weldable Grade 55 to be supplied at the supplier's option.
Matching nuts and washers
| Grade | Diameter | Plain finish nut | Galvanized nut | Washer |
|---|---|---|---|---|
| 36 | 1/2 – 1-1/2 in | A563 A hex | A563 A hex | F436 |
| 36 | 1-5/8 – 4 in | A563 A heavy hex | A563 A heavy hex | F436 |
| 55 | 1/2 – 1-1/2 in | A563 A hex | A563 A heavy hex | F436 |
| 55 | 1-5/8 – 4 in | A563 A heavy hex | A563 A heavy hex | F436 |
| 105 | 1/2 – 1-1/2 in | A563 D heavy hex | A563 DH heavy hex | F436 |
| 105 | 1-5/8 – 3 in | A563 DH heavy hex | A563 DH heavy hex | F436 |
- A563 Grade D nuts are hard to find; Grade DH or A194 2H heavy hex nuts are the usual substitutes for Grade 105.
- Base plates usually have oversized holes, so the drawing often calls for thick plate washers in addition to or instead of F436 washers. Include plate washer size and thickness in the RFQ.
Anchor bolt shapes
| Shape | How it anchors | Typical use | Dimensions to send |
|---|---|---|---|
| L-bend (90° hook) | Bent leg bears on concrete | Light columns, equipment pads | Overall length, thread length, leg length |
| J-hook | Curved hook | Light framing, sill plates | Overall length, thread length, hook dimensions |
| Headed | Forged head or welded plate at the bottom | Most structural columns; preferred for high loads | Length, thread length, head or plate size |
| Straight rod with nut and plate | Nut and plate washer embedded at the bottom | Large diameters, Grade 105 | Length, thread length at both ends, plate size |
| Double-end threaded rod | Embedded with nut or used with sleeves | Templates and adjustable setting | Length and both thread lengths |
- For Grade 105 and large diameters, drawings usually call for headed rods or nut-and-plate anchors rather than hooks. Follow the drawing; do not substitute a shape without the engineer's approval.
Approximate rod weight (lb per foot)
Calculated for full-diameter steel rod (density 0.2836 lb/in³). Threaded sections weigh slightly less. Use these to estimate freight for long anchor bolts.
| Diameter | lb / ft | kg / m | Diameter | lb / ft | kg / m |
|---|---|---|---|---|---|
| 1/2 in | 0.67 | 0.99 | 1 in | 2.67 | 3.98 |
| 5/8 in | 1.04 | 1.55 | 1-1/4 in | 4.18 | 6.22 |
| 3/4 in | 1.50 | 2.24 | 1-1/2 in | 6.01 | 8.95 |
| 7/8 in | 2.05 | 3.05 | 2 in | 10.7 | 15.9 |
Galvanizing anchor bolts
- Hot-dip galvanizing to ASTM F2329 is common for Grade 36 and 55 anchor rods in outdoor and coastal foundations. Galvanize nuts and washers with the rods; nuts must be tapped oversize.
- Galvanize the full rod or only the projecting end, as the drawing requires. Partial galvanizing must be stated clearly.
- Grade 105 is quenched and tempered to high hardness; check the project specification before galvanizing and ask how hydrogen embrittlement risk is controlled.
What to include in an anchor bolt RFQ
- Grade, and S1 if weldable Grade 55 is needed; colour coding or S3 stamping.
- Shape: L-bend, J-hook, headed, straight rod with nut and plate.
- Diameter, overall length, thread length and bend or hook dimensions, or a drawing.
- Finish: plain or hot-dip galvanized (ASTM F2329), full or partial.
- Nuts, F436 washers and plate washers per rod; templates if required; quantity per size.
- Destination country: EU importers should note that anchor bolts and threaded rods from China have carried EU anti-dumping duties of 54.7–72.3 % since October 2025; check the duty before ordering.
Frequently asked questions
Which F1554 grade is most common?
Grade 36 is the most widely used for general building columns. Grades 55 and 105 are used where the engineer needs higher strength.
Can Grade 55 be substituted for Grade 36?
Under F1554, a weldable Grade 55 may be supplied in place of Grade 36 at the supplier's option. Follow your project specification and engineer's approval.
Why are anchor bolt ends painted?
F1554 uses an end colour code to identify the grade on site: blue for 36, yellow for 55 and red for 105. Supplement S3 allows a permanent stamp instead.
Can F1554 Grade 55 be welded?
Only if supplement S1 is specified, which controls chemistry and carbon equivalent. Without S1, weldability is not assured.
What nut goes with F1554 Grade 105?
A563 Grade DH heavy hex nuts (or A194 2H) are normally used, because Grade D nuts are rarely available. Galvanized Grade 105 rods use galvanized DH nuts.
What is the MOQ for anchor bolts from HEXVARO?
Reference MOQ is 500 pcs per specification. Stock sizes typically ship in 10–15 days and made-to-order sizes in 25–30 days, subject to quotation. We reply to every RFQ within 2 working hours.
What colour is an F1554 Grade 105 anchor bolt?
Red. Grade 36 is blue and Grade 55 is yellow.