Many variables in metal conditioning and fastener formation can change the information below. Various sources have been used to provide the information below, and the use of this information is at the sole risk of the user. Marine Fasteners is not responsible for any loss, damage, or claim from the use of this information.

18-8 series Stainless

316 Stainless

Proof Load: None
Yield Strength: 30,000
Tensile Strength: 75,000

Diameter
1/4-3/4
3/4-1
1-1-1/4
1-1/4-1-1/2

Proof Load
None
None
None
None

Yield Strength
100,000
80,000
65,000
50,000

Tensile Strength
125,000
115,000
105,000
100,000

Clamp Load

Minimum Tensile - lbs 

Clamp Load

Minimum Tensile - lbs 

1/4-20

1350

2780

2100

4600

1/4-28

1500

3020

2400

5000

5/16-18

2200

4400

3400

7400

5/16-24

2400

4700

3800

7900

3/8-16

3200

6500

5100

10900

3/8-24

3700

9000

5700

15000

1/2-13

5900

11900

9350

19800

1/2-20

6700

12800

10550

21400

5/8-11

9500

18800

14950

31400

5/8-18

10800

20400

16850

34000

3/4-10

14100

27600

20300

42300

3/4-16

15700

29600

22670

45400

7/8-9

11700

37900

16850

58100

1-8

15300

49700

22900

69500

1-1/8-7

19300

62700

25400

87800

1-1/4-7

24500

78800

32200

110300

1-3/8-6

29200

94400

38400

125900

1-1/2-6

35600

114000

46700

152000

Materials: Stainless Steel

Tensile and yield will increase in austenitic stainless steel fasteners made by cold forming, may decrease in fasteners made by machining.

Alloy UNS
Designation		 Tensile
(ksi)		 Yield
(ksi)		 Approximate
Rockwell Hardness		 Carbon
(max)		 Manganese
(max)		 Phosphorus
(max)		 Sulfur
(max)		 Silicon Chromium Nickel Copper Other
Elements
18-8 - 80-150 40 min B85-95 0.08% 2% 0.2% 0.03-15% 1% 17-20% 8-13% 0-4% -
302 S30200 70-125 40 min B85-95 0.15% 2% 0.045% 0.03% 1% 17-19% 8-10% -
303 S30300 90-125 40 min B85-95 0.15% 2% 0.02% 0.15%min 1% 17-19% 8-10% -
304 S30400 85-150 40 min B85-95 0.08% 2% 0.45% 0.03% 1% 18-20% 8-10.5% 1%
304L S30403 Slightly lower than alloy 304 Slightly lower than alloy 304 Slightly lower than alloy 304 due 0.03% 2% 0.045% 0.03% 1% 18-20% 8-12% 1%
305 S30500 80-140 40 min B85-95 0.12% 2% 0.045% 0.03% 1% 17-19% 10.5-13% 1%
309 S30900 100-120 40 min B85-95 0.20% 2% 0.045% 0.03% 1% 22-24% 12-15% -
310 S31000 100-120 60-80 B85-95 0.25% 2% 0.045% 0.035% 1.5% 24-26% 19-22% -
316 S31600 85-140 40 min B85-95 0.08% 2% 0.045% 0.03% 1% 16-18% 10-14% 2-3%
316L S31603 Slightly lower than alloy 316 Slightly lower than alloy 316 Slightly lower than alloy 316 0.03% 2% 0.045% 0.03% 1% 16-18% 10-14% 2-3%
317 S31700 100-120 60-80 B85-95 0.08% 2% 0.045% 0.03% 1% 18-20% 11-15% 3-4%
321 S32100 100-120 60-80 B85-95 0.08% 2% 0.045% 0.03% 1% 17-19% 9-12% - Titanium
5 X Carbon
347 S34700 100-120 60-80 B85-95 0.08% 2% 0.045% 0.03% 1% 17-19% 9-13% - Columbian
Tantalum
10 X Carbon

Tensile and yield will increase sharply in martensitic stainless steel fasteners made by heat treating

Alloy UNS
Designation		 Tensile
(ksi)		 Yield
(ksi)		 Approximate
Rockwell Hardness		 Carbon
(max)		 Manganese
(max)		 Phosphorus
(max)		 Sulfur
(max)		 Silicon Chromium Nickel Copper Other
Elements
410 S41000 180 heat treated 150 heat treated C34 0.15% 1% 0.04% 0.03% 1% 11.5-13.5% - - -
416 S41600 180 heat treated 150 heat treated C34-45 0.15% 1.25% 0.06% 0.15%min 1% 12-14% - - -
420 S42000 250 heat treated 200 heat treated C45 0.15%min 1% 0.04% 0.03% 1% 12-14% - - -

Ferritic stainless steel

Alloy UNS
Designation		 Tensile
(ksi)		 Yield
(ksi)		 Approximate
Rockwell Hardness		 Carbon
(max)		 Manganese
(max)		 Phosphorus
(max)		 Sulfur
(max)		 Silicon Chromium Nickel Copper Other
Elements
405 S40500 70-75 40-45 B65-75 0.08% 1% 0.04% 0.03% 1% 11.5-14.5% - - 1-3%
Aluminum
430 S43000 70-75 40-45 B65-75 0.12% 1% 0.04% 0.03% 1% 16-18% - -

Austentic stainless steel, strain hardened bolts, screws, studs, and nuts shall
have the following strength per properites

Product Size

Bolts, Screws, Studs

Nuts

Tested Full Size

 Machine Test Specimens

Proof
Load
Stress

Yield
Strength

Tensile
Strength

Yield
Strength

Tensile
Strength

in

min psi

min psi

min psi

min psi

psi
to 5/8 in

100,000

125,000

90,000

115,000

125,000
over 5/8 to 1 in

70,000

105,000

65,000

100,000

105,000
over 1 to 1-1/2 in

50,000

90,000

45,000

85,000

90,000

Type #

Density
lbs/in³

Spcific Heat
BTU/° F/lb
0-100 °C

Thermal
Conductivity
BTU/Ft²/Ft/Hr/°F
100 °C

Coefficient of
Thermal Expansion
Per °F x10-6
0-100 °C

Electrical
Resistivty
Micohm-cm
21 °C

Magnetic
Permeability
(Annealed)

302

.29

.12

9.4

9.6

72.0

1.008

304

.29

.12

9.4

9.6

70.0

1.008

304L

.29

.12

9.4

9.6

70.0

1.008

316

.29

.12

9.4

8.9

74.0

1.008

316L

.29

.12

9.4

8.9

74.0

1.008

Type #
Annealed

Tensile
Strength
1000 psi

Yield
Strength
1000 psi

Elongation in
2 inches, %

Reducton of
Area, %

Brinell
Hardness

302

90

40

55

70

150

304

85

35

55

70

150

304L

80

30

55

70

140

316

85

35

60

70

150

316L

78

30

55

65

145

more