MF FASTENER INDUSTRIES LLC Manufacturer of anchor bolts, studs & plate washers · Importer & stockist of fasteners

Technical datasheet ASTM F3125 / F3125M — Grade A325 & A325M heavy hex structural bolt

Reference only — for design, verification or contractual purposes refer to the current issue of the original standard. MF Fastener Industries LLC · sales@mfindllc.com · +971 6 767 2469 · mfindllc.com

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Dimensional datasheet

ASTM A325 structural bolt

Heavy hex structural bolt, quenched and tempered, 120 ksi / 830 MPa class. The workhorse bolt for steel-to-steel structural connections. Now a grade within ASTM F3125.

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D nominal diameterF width across flatsH head heightL length under head

Dimensions

inches

Imperial sizes, UNC thread, dimensions to ASME B18.2.6. Heavy hex heads are larger across flats than a standard hex bolt of the same diameter — they are not interchangeable.

Size	Threads/in	F — across flats	Spanner size	H — head height	Thread length	Tensile strength min
1/2"	13 UNC	7/8"	7/8"	5/16"	1"	120 ksi
5/8"	11 UNC	1-1/16"	1-1/16"	25/64"	1-1/4"	120 ksi
3/4"	10 UNC	1-1/4"	1-1/4"	15/32"	1-3/8"	120 ksi
7/8"	9 UNC	1-7/16"	1-7/16"	35/64"	1-1/2"	120 ksi
1"	8 UNC	1-5/8"	1-5/8"	39/64"	1-3/4"	120 ksi
1-1/8"	7 UNC	1-13/16"	1-13/16"	11/16"	2"	105 ksi
1-1/4"	7 UNC	2"	2"	25/32"	2"	105 ksi
1-3/8"	6 UNC	2-3/16"	2-3/16"	27/32"	2-1/4"	105 ksi
1-1/2"	6 UNC	2-3/8"	2-3/8"	15/16"	2-1/4"	105 ksi

A325 and A490 are withdrawn as standalone standards

ASTM withdrew A325, A325M, A490 and A490M in 2016. All four are now grades within ASTM F3125 / F3125M. The product is unchanged and the head is still marked A325 or A490, so a drawing calling for A325 is satisfied by F3125 Grade A325.

Type 1 and Type 3

Type 1 is carbon or alloy steel, plain or galvanized. Type 3 is weathering steel, marked A325 with an underline, for uncoated weathering assemblies. Do not mix Types in one connection.

Galvanized A325 is supplied as a tested assembly

The nut is tapped oversize and lubricated by the galvanizer, and bolt, nut and washer are rotational-capacity tested together as a lot. Splitting the assembly voids that test — order and keep them together.

Metric — Grade A325M

ASTM F3125M

Size	Pitch	F — across flats	Spanner size	H — head height	Tensile min
M16	2.00	27 mm	27 mm	10.0 mm	830 MPa
M20	2.50	34 mm	34 mm	12.5 mm	830 MPa
M22	2.50	36 mm	36 mm	14.0 mm	830 MPa
M24	3.00	41 mm	41 mm	15.0 mm	830 MPa
M27	3.00	46 mm	46 mm	17.0 mm	830 MPa
M30	3.50	50 mm	50 mm	18.7 mm	830 MPa
M36	4.00	60 mm	60 mm	22.5 mm	830 MPa

A325M is not a soft conversion of A325 — separate dimensions, separate certification. An M20 is not a 3/4 inch bolt.

Mechanical properties

F3125 / F3125M

Property	A325 (imperial)	A325M (metric)
Tensile strength min	120 ksi to 1 in · 105 ksi over	830 MPa
Yield strength min	92 ksi to 1 in · 81 ksi over	660 MPa
Hardness	25 – 34 HRC	25 – 34 HRC
Elongation min	14%	14%
Head marking	A325 and manufacturer's mark	A325M and manufacturer's mark

Bolts are marked on the head. An unmarked bolt in a structural connection cannot be verified and should be rejected.

At a glance

Standard	ASTM F3125 / F3125M Grade A325 / A325M
Withdrawn standard	ASTM A325 · A325M (2016)
Head	Heavy hexagon
Thread	UNC imperial · metric coarse
Class	120 ksi / 830 MPa
Matching nut	ASTM A563 Grade C or DH · A563M 8S or 10S
Matching washer	ASTM F436 / F436M hardened
Load indicator	ASTM F959 / F959M DTI washer

Supply

Imported and held in stock, sourced from established mills and supplied from our warehouse in Umm Al Quwain.

Anchor bolts, studs and plate washers are manufactured at our own plant. This item is not.

Finish

Plain	Black, oiled
Hot-dip galvanized	To F2329, supplied as a tested assembly
Mechanically galvanized	Class 50 or 55
Certification	Mill certificate against lot and heat number

Testing

Dimensional and thread inspection is carried out in our own plant on calibrated instruments. Tensile, hardness and chemical testing is carried out by independent UAE-accredited laboratories.

Reference only

This datasheet is published for reference. Dimensions and property values are reproduced in good faith from published standards, but for design, verification or contractual purposes always refer to the current issue of the original standard.

If a figure here conflicts with the standard, the standard governs.

Need a quotation?

Send the size, length, Type, finish and quantity, and say whether you need nuts and washers as a matched assembly. For galvanized work, order the assembly.