Scale

Indenter

Preliminary
Force
P (kgf)

Total
Test Force
F (kgf)

Application

HRA

Diamond

10

60

Cemented carbides, thin steel, shallow case-hardened steel

HRB

Ball 1/16” dia.

10

100

Cu and Al alloys; soft steels, malleable iron, annealed low C steels, etc.

HRC

Diamond

10

150

Hard steels, hard cast irons, pearlitic malleable iron, titanium, deep case-hardened steel, etc.

HRD

Diamond

10

100

Thin hard steel, med. case-hardened steel, and pearlitic malleable iron

HRE

Ball 1/8” dia.

10

100

Al and Mg alloys; cast iron, bearing metals

HRF

Ball 1/16” dia.

10

60

Annealed Cu alloys, thin soft sheet metals

HRG

Ball 1/16” dia.

10

150

Bronze (Cu-Ni-Zn and Cu-Ni alloys), malleable irons

HRH

Ball 1/8” dia.

10

60

Soft materials, high ferritic, Al, Pb, Zn

HRK

Ball 1/8” dia.

10

150

Bearing metals and other very soft or thin materials, such as thermoplastics, thermosets, rubbers

HRL

Ball ¼” dia.

10

60

HRM

Ball ¼” dia.

10

100

HRP

Ball ¼” dia.

10

150

HRR

Ball ½” dia.

10

60

HRS

Ball ½” dia.

10

100

HRV

Ball ½” dia.

10

150

HR 15N

Diamond

3

15

Rockwell superficial scales are used to test materials too thin for the regular scales.  Generally, the diamond indenter are used for hard materials, and ball indenters are used on soft material
Hardness tests used for thin sheets,
foils, coatings, surface heat
treatments, and polymers including
their surface treatments

HR 30N

Diamond

3

30

HR 45N

Diamond

3

45

HR 15T

Ball 1/16” dia.

3

15

HR 30T

Ball 1/16” dia.

3

30

HR 45T

Ball 1/16” dia.

3

45

HR 15W

Ball 1/8” dia.

3

15

HR 30W

Ball 1/8” dia.

3

30

HR 45W

Ball 1/8” dia.

3

45

HR 15X

Ball ¼” dia.

3

15

HR 30X

Ball ¼” dia.

3

30

HR 45X

Ball ¼” dia.

3

45

HR 15Y

Ball ½” dia.

3

15

HR 30Y

Ball ½” dia.

3

30

HR 45Y

Ball ½” dia.

3

45