ASTM A325 Grades

A325 Types

TYPE 1 - Medium carbon, carbon boron, or medium carbon alloy steel.

TYPE 2 - Withdrawn November 1991.

TYPE 3 - Weathering steel.


T - Fully threaded A325. (Restricted to 4 times the diameter in length)

M - Metric A325


SC - Slip critical connection.

N - Bearing type connection with threads included in the shear plane.

X - Bearing type connection with threads excluded from the shear plane.


A325 Mechanical Properties
Size Tensile, ksi Yield, ksi Elong. %, min RA, % min
1/2 - 1 120 min 92 min 14 35
11/8 - 11/2 105 min 81 min 14 35

A325 Type 1 Chemical Properties
Heat Analysis 120ksi, % 150ksi, %
Carbon 0.30 - 0.52 0.30 - 0.48*
Manganese 0.60 min 0.60 min
Phosphorus 0.035 max 0.035 max
Sulfur 0.040 max 0.040 max
Silicon 0.15 - 0.30 -
Boron 0.003 max 0.003 max
Copper - -
Nickel - -
Chromium - -
Molybdenum - -

*Carbon 0.35-0.53% for 1-1/2” A490/150ksi bolts


A325 Type 3 Chemical Properties
Heat Analysis 120ksi, % Comp A 120ksi, % Comp B 120ksi, % Index 150ksi, % Index
Carbon 0.33 - 0.40 0.38 - 0.48 0.30 - 0.52 0.30 - 0.53
Manganese 0.90 - 1.20 0.70 - 0.90 0.60 min 0.60 min
Phosphorus 0.035 max 0.035 max 0.035 max 0.035 max
Sulfur 0.040 max 0.040 max 0.040 max 0.040 max
Silicon 0.15 - 0.30 0.30 - 0.50 - -
Copper 0.25 - 0.45 0.20 - 0.40 0.20 - 0.60 0.20 - 0.60
Nickel 0.25 - 0.45 0.50 - 0.80 0.20 min* 0.20 min*
Chromium 0.45 - 0.65 0.50 - 0.80 0.20 min 0.20 min
Molybdenum - 0.06 max 0.10 min* 0.10 min*

*Either Nickel or Molybdenum must be present in the amount specified *Corrosion Index based on ASTM Guide G101


A325 Recommended Hardware
Nuts Washers
Type 1 Type 3 Type 1 Type 3
Plain Galvanized Plain
A563C, C3, D, DH, DH3 A563DH A563C3, DH3 F436-1 F436-3

Note: Nuts conforming to A194 Grade 2H are a suitable substitute for use with A325 heavy hex structural bolts. The ASTM A563 Nut Compatibility Chart has a complete list of specifications.


All information derived from globally recognized specifications, subject to change, user discretion is advised.