The plain, low-strength carbon-steel bolt — the one you reach for when a job doesn’t need a high grade. Also the common anchor bolt.
ASTM A307 covers low-carbon-steel bolts and studs for general and anchor use — minimum 60 ksi tensile, no heat treatment. It’s the everyday, economical choice where high strength isn’t required, and the basis for most bent and straight anchor bolts.
Low-strength carbon bolts & anchors
Often “A307A” / “307A”, or unmarked
General structural, anchor & foundation bolts
| Grade | Tensile | Yield | Typical use |
|---|---|---|---|
| Grade A | 60 ksi min | — | General & anchor bolts |
| Grade B | 60–100 ksi | — | Cast-iron flanged pipe joints |
A307 is the low-load workhorse: bent and straight anchor bolts set in concrete, general building hardware, and any bolted joint that doesn’t need a graded fastener. It covers a lot of ground — just not the high-strength structural connections, which call for A325 or A490 instead.
For anchor rods that need a defined strength grade (and an engineer’s stamp), step up to ASTM F1554.
A307 bolts are plain — no Grade 5/8 radial lines. Some are stamped “A307A” or “307A”; many are unmarked. If a bolt has no grade marks and isn’t stainless, it’s usually an A307-class fastener. Bring it in if you’re unsure.
Hex bolts, all-thread, and bent / straight anchor bolts in A307 — cut and bent to your job. Tell us the size and length, or bring a sample.
