Speedy Metals Information for 8620 HR Plate

AISI 8620 HR Plate is an alloy carburizing steel when thermally treated develops a hard outer case with a soft ductile core. Carefully controlled proportions of chromium, nickel and molybdenum are responsible for the extensive use as a carburizing alloy steel, with valuable features including extreme surface hardenability and good internal strength. Has minimum distortion and growth characteristics. 8620 has good machinability and responds well to polishing.

ANALYSIS

MECHANICAL PROPERTIES

The above values are average and may be considered as representative of 8620 hot roll plate

APPLICATIONS

8620 applications include gears, gear racks, pinions, cams, cranks, clutch shafts, shafting, axles, tie bars, collets, bushings, heavy duty pins, bolting, springs, hand tools, die cases, tool holders, bolsters, backing plates, pressure plates, die shoes, chuck jaws, ring gears, and a multitude of machinery parts and components

MACHINEABILITY AND WELDABILITY

8620 Plate has a machinability rating at 60% of B1112. Average cutting speed 100 ft/min. 8620 Plate can be forged at 2200° down to 1800° F prior to hardening or carburizing. 8620 Plate is excellent for welding applications.

HEAT TREATING

8620 can be hardened to 1500° F followed by water quench. Carburize at 1650° - 1700° F in an appropriate carburizing medium and oil quench to harden. Tempering of carburized parts is done at 250° - 300° F and will result in the alloy having a core strength of approximately 135,000 psi minimum. Tempering of heat treated and water quenched parts (not carburized) is done at 400° - 1300° F, with greater hardness the lower the tempering temperature.

TOLERANCES

Thickness

	Tolerance Over Specified Thickness, For Widths Given, in Inches
Thickness (Inches)	Thru 47	48 to 59	60 to 71	72 to 83	84 to 95	96 to 107	108 to 119	120 to 131	132 to 143	144 to 167
To under 1/4	0.030	0.030	0.030	0.030	0.030	0.030	0.030	0.030	0.040	-
1/4 to under 5/16	0.030	0.030	0.030	0.030	0.030	0.030	0.030	0.040	0.040	-
5/16 to under 3/8	0.030	0.030	0.030	0.030	0.030	0.030	0.030	0.040	0.040	0.050
3/8 to under 5/8	0.030	0.030	0.030	0.030	0.030	0.030	0.040	0.040	0.050	0.060
3/4 to under 1	0.030	0.030	0.030	0.030	0.040	0.040	0.050	0.050	0.060	0.070
1 to under 2	0.060	0.060	0.060	0.060	0.060	0.070	0.080	0.100	0.100	0.110
2 to under 3	0.090	0.090	0.090	0.100	0.100	0.110	0.120	0.130	0.140	0.150
3 to under 4	0.110	0.110	0.110	0.110	0.110	0.130	0.140	0.140	0.140	0.150
4 to under 6	0.150	0.150	0.150	0.150	0.150	0.150	0.150	0.150	0.150	0.200
6 to under 10	0.230	0.240	0.240	0.240	0.240	0.240	0.240	0.240	0.240	0.270

Tolerance under specified thickness .010" x 3/4 x 52" wide plate, for example, would have a tolerance range of .740-.780"
Because of tolerances, ie thickness, flatness and camber, as well as the hot roll condition, ASTM A36 generally does not finish to specified thickness.

Camber

Permissible camber for sheared and Gas-Cut A36 Plate, All Thicknesses:

Maximum Camber (Inches) = 1/8" x ( Number of feet of length / 5 )

Flatness

For all plates, the longest dimension is considered the length, and flatness tolerance along the length should not exceed the amounts indicated below the specified width and thickness in plate though 12' in length or longer. The flatness variations across the width should not exceed the tabular amount for the specified width

	Flatness Tolerances For Specified Widths, in Inches (Maximum deviation from a horizontal flat surface)
Thickness	Lbs/Sq. FT	> 36	36 > 48	48 > 60	60 > 72	72 > 84	84 > 96	96>108
Under 1/4"	> 10.2#	0.813	1.125	1.375	1.875	2.000	2.250	2.375
1/4 to under 3/8	10.2 > 15.3	0.750	0.938	1.125	1.375	1.750	1.875	2.000
3/8 to under 1/2	15.3 > 20.4	0.750	0.875	0.938	0.938	1.125	1.313	1.500
1/2 to under 3/4	20.4 > 30.6	0.625	0.750	0.813	0.875	1.000	1.125	1.250
3/4 to under 1	30.6 > 40.8	0.625	0.750	0.875	0.875	0.938	1.000	1.125
1 to under 2	40.8 > 81.7	0.563	0.625	0.750	0.813	0.875	0.938	1.000
2 to under 4	81.7 > 163.4	0.500	0.563	0.688	0.750	0.750	0.750	0.750
4 to under 6	163.4 > 245.0	0.563	0.688	0.750	0.750	0.875	0.875	0.938
6 to under 8	245.0 > 326.7	0.625	0.750	0.750	0.938	1.000	1.125	1.250

1/2" 8620 Hot Rolled, Steel Plat	5/8" 8620 Hot Rolled, Steel Plat	3/4" 8620 Hot Rolled, Steel Plat
1" 8620 Hot Rolled, Steel Plat	1-1/8" 8620 Hot Rolled, Steel Plat	1-1/4" 8620 Hot Rolled, Steel Plat
1-1/2" 8620 Hot Rolled, Steel Plat	1-3/4" 8620 Hot Rolled, Steel Plat	2" 8620 Hot Rolled, Steel Plat
2-1/4" 8620 Hot Rolled, Steel Plat	2-1/2" 8620 Hot Rolled, Steel Plat	3" 8620 Hot Rolled, Steel Plat
3-1/4" 8620 Hot Rolled, Steel Plat	4" 8620 Hot Rolled, Steel Plat	4-1/2" 8620 Hot Rolled, Steel Plat
5" 8620 Hot Rolled, Steel Plat

8620 HR Plate