Fastener Specifications
The specs that show up on prints and POs — SAE and ASTM — in plain English. What each one is, how strong it is, and when you’d reach for it.
A spec callout like “A325” or “B7” is shorthand for a whole set of requirements — material, strength, and how it’s made. Here are the ones we stock and sell most, grouped by what they’re for. Each page keeps it plain and points you to the matching nuts, washers, and charts.
Which spec goes where
The mark on each card below is what you’ll find stamped on the part. F1554 rods are color-coded on the end instead: blue Gr 36, yellow Gr 55, red Gr 105.
SAE — general & automotive
The grade system you meet on everyday hardware and in machinery.
Metric — ISO property classes
The strength system on metric bolts — the number on the head is the grade.
ASTM — structural & general bolts
Steel-construction and iron-work bolting, plus general structural and anchor bolts.
General & anchor bolts
Low-strength carbon-steel bolts for general structural use and anchoring — the everyday workhorse.
Read the spec → ASTM A325Structural heavy hex bolts
Heat-treated structural bolts for steel connections. Now published as F3125 Grade A325.
Read the spec → ASTM A490High-strength structural bolts
Alloy-steel structural bolts where A325 isn’t enough. Now F3125 Grade A490 — and never galvanized.
Read the spec → ASTM F436Hardened structural washers
The through-hardened washer that goes with A325 and A490 bolts — flat or beveled.
Read the spec → ASTM A449Quenched & tempered bolts
Grade 5 strength in the ASTM world, up to 3″ — a common anchor-bolt and structural call-out.
Read the spec → ASTM A354Grade BD & BC bolts and studs
Alloy, quenched and tempered — Grade 8 strength in diameters up to 4″.
Read the spec →ASTM — studs & nuts (heat & pressure)
Flange and pressure-piping bolting — the stud-and-nut combos you’ll see on flanged joints, hot and cold service.
Alloy stud bolts
The standard high-strength stud for flanges and pressure piping — chrome-moly alloy, heat treated.
Read the spec → ASTM A194 2HHeavy hex nuts
The heavy hex nut that pairs with B7 studs and A325 bolts — marked “2H.”
Read the spec → ASTM A320 L7Low-temp stud bolts
B7’s cold-service cousin — same strength, impact-tested for low temperatures. Pairs with Grade 4/7 nuts.
Read the spec → ASTM A193 B8 / B8MStainless stud bolts
304 (B8) and 316 (B8M) stainless studs for corrosive service — picked for what they resist, not raw strength.
Read the spec →ASTM — anchor rods
Anchoring columns, equipment, and structures to concrete foundations.