|
|
| Head Marking |
Grade and
Material |
Nominal Size Range
(inches) |
Mechanical Properties |
Proof Load
(psi) |
Min. Yield Strength
(psi) |
Min. Tensile Strength
(psi) |
|
307A
Low carbon steel |
1/4"
thru 4" |
N/A |
N/A |
60,000 |
No Markings |
Grade 2
Low or medium carbon steel |
1/4" thru 3/4" |
55,000 |
57,000 |
74,000 |
| Over 3/4" thru 1-1/2" |
33,000 |
36,000 |
60,000 |
3 Radial Lines |
Grade 5
Medium carbon steel, quenched and tempered |
1/4"
thru 1" |
85,000 |
92,000 |
120,000 |
| Over
1" thru 1-1/2" |
74,000 |
81,000 |
105,000 |
6 Radial Lines |
Grade 8
Medium carbon alloy steel, quenched and tempered |
1/4"
thru 1-1/2" |
120,000 |
130,000 |
150,000 |
 |
Grade A325
Carbon or alloy steel with or without boron |
1/2"
thru 1-1/2" |
85,000 |
92,000 |
120,000 |
| Stainless Markings Vary |
18-8 & 316 Stainless
Steel alloy with chromium and nickel |
All sizes thru 1" |
N/A |
20,000 Min. 65,000 Typical |
65,000 Min. 100,000 – 150,000 Typical |
|
651 Silicon bronze
An alloy of mostly copper and tin with a small amount of silicon |
1/4"
thru 3/4" |
N/A |
55,000 |
70,000 |
| 7/8" thru 1-1/2" |
N/A |
40,000 |
55,000 |
|
Aluminum 2024
Aluminum alloy with copper, magnesium and manganese; solution heat treated and age hardened |
All sizes |
N/A |
36,000 |
55,000 |
|
|
| Head Marking |
Class and
Material |
Nominal Size Range
(mm) |
Mechanical Properties |
Proof Load
(MPa) |
Min. Yield Strength
(MPa) |
Min. Tensile Strength
(MPa) |
 |
Class 8.8
Medium carbon steel, quenched and tempered |
All sizes below 16mm |
580 |
640
|
800
|
| 16mm - 72mm |
600 |
660 |
830 |
 |
Class 10.9
Alloy steel, quenched and tempered |
5mm - 100mm |
830 |
940
|
1040
|
 |
Class 12.9
Alloy steel, quenched and tempered |
1.6mm - 100mm |
970 |
1100
|
1220
|
|
Usually Stamped A-2 or A-4 |
A-2 & A-4 Stainless
Steel alloy with chromium and nickel |
All sizes thru 20mm |
N/A |
210 Min.
450 Typical
|
500 Min.
700 Typical
|
|
Tensile Strength: The maximum load in tension (pulling apart) which a material can withstand before breaking or fracturing.
Yield Strength: The maximum load at which a material exhibits a specific permanent deformation.
Proof Load: An axial tensile load which the product must withstand without evidence of any permanent set.
1MPa = 1N/mm2 = 145 pounds/inch2
|