Resources

General Fastener Technical services

Carbon Steel Physical Properties

Corrosion Resistance:

Early fasteners relied on applying a thin layer of .00015 inch to .0005 inch of Electro-deposited zinc plating with .0003 being the norm. This was done in order to prolong the fastener life and to improve the appearance. A considerable number of years ago, Atlas pioneered the introduction and use of the Mechanical-Zinc plating process, which eliminates Hydrogen-embrittlement in the manufacturing process. One more advantage is the increased thickness range of deposited zinc ranging from .0003 inch to .001 inch, with .0005 being the norm.

Prior to plating, all carbon steel fasteners are case-hardened to create a hard surface for drilling and tapping while maintaining a softer core for ductility. Parts can also have added corrosion protection, by optionally coating fasteners with long life coating, either alone or in conjunction with a conventional paint finish that substantially increases the life of the fastener.

Metal Composition:

C .20-.25
Mn .80-1.10
P .040
S .050

Specific Gravity7.75
Density
lb/in³0.280
kg/m³7,750
Mean Specific Heat
Btu/ib °F (32/212°F)0.11
J/kg K (0/100°C)460
Electrical Resistivity (RT)
ohm-cir mil/ft343
microhm-mm570
Mean Coefficient of Thermal Expansion
10-6/°F(32/1200°F)6.5
10-6k(0/649°C)11.7
Thermal Conductivity
Btu in/fth²h °F(212V)173
Wm K(100°C)25.0
Modulus of Elasticity (E)
ksi29.0 x 103
MPa200 x 103

 

410 SS Physical Properties

Corrosion Resistance:

Stainless Type 410, in both annealed and heat-treated conditions, provides good corrosion resistance to mild atmospheres. It resists corrosion in many light industrial and domestic environments as well as potable and mine waters.

The alloy has acceptable resistance to sulfide stress cracking at Rockwell C 22 maximum hardness per NACE MR-01-75, "Sulfide-Stress-Cracking-Resistant Metallic Materials for Oil Field Equipment." Refer to the current document for details on acceptable conditions.

For optimum corrosion resistance, surfaces must be free of scale and foreign particles and finished parts should be passivated.

Metal Composition:

C .15
Mn 1.00
P .040
S .030
Si 1.00
Cr 11.5 - 13.5

Specific Gravity7.75
Density
lb/in³0.280
kg/m³7,750
Mean Specific Heat
Btu/ib °F (32/212°F)0.11
J/kg K (0/100°C)460
Electrical Resistivity (RT)
ohm-cir mil/ft343
microhm-mm570
Mean Coefficient of Thermal Expansion
10-6/°F(32/1200°F)6.5
10-6k(0/649°C)11.7
Thermal Conductivity
Btu in/fth²h °F(212V)173
Wm K(100°C)25.0
Modulus of Elasticity (E)
ksi29.0 x 103
MPa200 x 103

304 SS Physical Properties

Corrosion Resistance:

Annealed Project 70 stainless Type 304 is resistant to atmospheric corrosion, foodstuffs, sterilizing solutions, many organic chemicals and dyestuffs, and a wide variety of inorganic chemicals.

Intergranular corrosion may be a problem if the material is heated between 800°F (427°C) and 1650°F and (899°C) or cooled slowly through that range.

For optimum corrosion resistance, surfaces must be free of scale and foreign particles and finished parts should be passivated.

Metal Composition:

C .08
Mn 2.00
P .045
S .030
Si 1.00
Cr 18.0 - 20.0
Ni 8.0 - 10.5

Specific Gravity7.90
Density
lb/in³0.285
kg/m³7,900
Mean Specific Heat
Btu/ib °F (32/212°F)0.12
J/kg K (0/100°C)500
Electrical Resistivity (RT)
ohm-cir mil/ft433
microhm-mm720
Mean Coefficient of Thermal Expansion
10-6/°F(32/1200°F)10.4
10-6k(0/649°C)18.7
Thermal Conductivity
Btu in/fth²h °F(212V)113
Wm K(100°C)16.3
Modulus of Elasticity (E)
ksi28.0 x 103
MPa193 x 103

CARBON &410 STAINLESS STEEL
Fastener Strength(TENSILE VALUES ARE FOR HEX WASHER HEAD & HEX HEAD FASTENERS)
FASTENER DIAMETERMINIMUM TENSILE (LBS.)MINIMUM TORQUE (IN LBS.)MINIMUM SHEAR (LBS.)
#6-201,12525750
#8-181,575421,000
#9-162,350651,500
#10-162,100611,400
#10-242,350651,500
#12-142,800922,000
#12-243,2501002,100
1/4-204,2751682,700
#17-145,2001753,125
#18-94,5501702,575

304 STAINLESS STEEL
Fastener Strength(TENSILE VALUES ARE FOR HEX WASHER HEAD & HEX HEAD FASTENERS)
FASTENER DIAMETERMINIMUM TENSILE (LBS.)MINIMUM TORQUE (IN LBS.)MINIMUM SHEAR (LBS.)
#14-102,9251251,925
1/4-143,6001502,600
#17-145,2001703,125

DECIMAL (INCH) EQUIVALENTDECIMAL (INCH) EQUIVALENT
THREAD DIAMETERDECIMAL EQUIVALENTGAUGETHICKNESS (IN.)
#6.14026.018
#7.15024.024
#8.16022.030
#9.18020.036
#10.19018.048
#11.20016.060
#12.21014.075
#13.23012.105
1/4".24010.134
#14.2508.164
#17.2854.224
#18.3041/4.250
11/32".344

RECOMMENDED DRIVING SPEED
DRILLING FASTENERSELECTRIC SCREW GUN WITH DEPTH SENSING NOSE PIECE
#6 THRU #102,500 RPM MAX
#12 THRU #18 TCP 1, 2, 32,000 RPM MAX
#12 THRU 1/4 TCP 4, 51,800 RPM MAX
SELF-TAPPING FASTENERS
CARBON & 410 STAINLESS2,000 RPM MAX
.300 STAINLESS800 RPM MAX

FASTENER SIZEWASHER O.D
#8 THRU #101/2"
#12 THRU 1/4"15MM
#1815MM

Metal to Metal Fastening to Determine Drilling Tip Length

The length of the tip required on a drilling fastener is determined by adding up the thickness of the top material, any insulation or void between the top material and bottom material, and the thickness of the bottom material. If a hole larger than the screw thread has been pre-drilled or punched into the top material, only the thickness of the bottom material need be considered. The threaded portion of the shank must be long enough to extend into and through the bottom material drilled.

metal-metal-fastening diagram

Socket Information

Recommend 5/16" retaining ring socket, which allows good fastener head engagement into socket and keeps fastener perpendicular to the work surface. If magnetic sockets are used, be sure to set magnet depth prior to use.

socket-engagement diagram

Washer Seating Recommendation

washer-seating correct diagram
fastener-selection-guide

Fastener Selection

to minimize Galvanic Action (Corrosion) Between Fastener and Base Metal

FASTENER METAL
BASE METALZINC & GALVANIZED STEELALUMINUM & ALUMINUM ALLOYSSTEEL & CAST IRONBRASS, COPPER, BRONZE, MONELMARTENSITIC STAINLESS 410AUSTENITIC STAINLESS 302/304, 303, 305
ZINC & GALANIZED STEELABBCCC
ALUMINUM & ALUMINUM ALLOYSAABCNRB
STEEL & CAST IRONADAACCB
TERNE (LEAD-TIN) PLATED SHEETADEAEAECCB
BRASS, COPPER, BRONZE, MONELADEAEAEAAB
FERRITIC STAINLESS STEEL (430)ADEAEAEAAA
AUSTENITIC STAINLESS STEEL (302/304)ADEAEAEAEAA

KEY

A - corrosion of the base metal is not increased by the fastener
B - corrosion of the base metal is marginally increased by the fastener
C - corrosion of the base metal may be markedly increased by the fastener
D - plating on the fastener is rapidly consumed, leaving the bare fastener metal
E - corrosion of the fastener is increased by the base metal
NR - not recommended
Note: Surface treatment and environment can change activity.

 

Fastener Selection Chart and Suggested Drill Sizes

FASTENER SELECTION CHART AND SUGGESTED DRILL SIZES
#14 TYPE A 1/4" TYPE B & BP1/4" TYPE B & BP1/4" TYPE AB#17 TYPE AB
STEEL GAUGEHOLE SIZESTEEL GAUGEHOLE SIZESTEEL GAUGEHOLE SIZESTEEL GAUGEHOLE SIZE
#261/8"3/16"-3/8"#2 BIT#261/8"#263/16"
#245/32"3/8" & OVER#1 BIT#245/32"#243/16"
#225/32"#225/32"#223/16"
#205/32"#205/32"#201/4"
#183/16"#183/16"#181/4"
#163/16"#163/16"#161/4"
#14#7 BIT#14#7 BIT#141/4"
#12#7 BIT#141/4"
1/8"#2 BIT#1016/64"
#10#2 BIT

All test results and recommendations are based on laboratory tests. Hole sizes for material thicker than 14 gauge are based on 50,000 psi hot rolled structural steel. Specific job site conditions should be taken into consideration when specifying the proper fastener. Because applications vary, we assume no liability for use of this information.