Technical Specifications - Fastener Standards & Specifications

ASTM Specifications

Carbon Steel Fasteners

Specification	Description	Grade/Class	Tensile Strength	Application
ASTM A193	Alloy Steel & Stainless Steel Bolting	B7, B8, B8M, B16	860-1035 MPa	High temperature service
ASTM A194	Carbon & Alloy Steel Nuts	2H, 2HM, 7, 8, 8M	Matching A193	Pressure vessels, piping
ASTM A307	Carbon Steel Bolts & Studs	Grade A, B	415-550 MPa	General purpose applications
ASTM A320	Alloy Steel Bolting - Low Temp	L7, L7M, L43	860-1035 MPa	Cryogenic service
ASTM A325	Structural Bolts, Heat Treated	Type 1, 2, 3	830-1035 MPa	Structural steel connections
ASTM A490	Heat Treated Steel Structural Bolts	Type 1, 2, 3	1035-1380 MPa	Heavy structural applications

Stainless Steel Fasteners

Specification	Material Grade	UNS Number	Tensile Strength	Corrosion Resistance
ASTM F593	304, 316, 410	S30400, S31600, S41000	515-860 MPa	General corrosion resistance
ASTM F594	304, 316, 410	S30400, S31600, S41000	515-860 MPa	Stainless steel nuts
ASTM A453	660, 665	S66286, S66545	965-1170 MPa	High temp, high strength
ASTM A286	Alloy 660	S66286	930-1070 MPa	High temp service to 650°C

ISO & DIN Standards

Standard	Description	Property Class	Equivalent
ISO 898-1	Mechanical Properties of Bolts	4.6, 5.8, 8.8, 10.9, 12.9	ASTM A307, SAE J429
ISO 898-2	Mechanical Properties of Nuts	4, 5, 8, 10, 12	ASTM A194, SAE J995
DIN 931	Hexagon Head Bolts	4.6 to 12.9	ISO 4014
DIN 934	Hexagon Nuts	4 to 12	ISO 4032
DIN 125	Flat Washers	Various sizes	ISO 7089, 7090
DIN 6885	Parallel Keys	Type A, B	ISO 2491

ASME & ANSI Standards

ASME B16.5 - Pipe Flanges and Flanged Fittings

Covers pressure-temperature ratings, materials, dimensions, tolerances, marking, testing, and methods of designating openings for pipe flanges and flanged fittings. Available in pressure classes: 150, 300, 600, 900, 1500, 2500.

ASME B18.2.1 - Square, Hex, Heavy Hex and Askew Head Bolts

Dimensional standards for square and hex bolts and screws. Covers nominal sizes from 1/4" through 4" diameter with various thread series (UNC, UNF, 8UN).

ASME B18.2.2 - Square and Hex Nuts

Dimensional requirements for square nuts, hex nuts, hex jam nuts, hex slotted nuts, heavy hex nuts, and heavy hex jam nuts.

Material Property Classes

Property Class	Nominal Tensile Strength (MPa)	Proof Stress (MPa)	Material	Typical Application
4.6	400	240	Low/medium carbon steel	Light duty applications
5.8	500	400	Low/medium carbon steel	General engineering
8.8	800	640	Medium carbon steel, Q&T	Automotive, machinery
10.9	1000	900	Alloy steel, Q&T	High strength applications
12.9	1200	1080	Alloy steel, Q&T	Critical high stress

Note: Property Class Interpretation

The property class designation (e.g., 8.8) consists of two numbers:

First number (8) = 1/100 of nominal tensile strength (800 MPa)
Second number (8) = 10 times the ratio of proof stress to tensile strength (8/10 = 0.8)
Proof stress = 800 × 0.8 = 640 MPa