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Hardness Conversion Chart

Inch Fractions

Inch Decimals

Metric
(mm)
Weight 1000 balls (kg) Approximate Qty per Litre Inch Fractions Inch Decimals Metric
(mm)
Weight 1000 balls (kg)
1/64 .0156 0.397 .00026 - - .7480 19.000 27.98
- .0197 0.500 .00051 - 3/4 .7500 19.050 28.20
1/32 .0312 0.794 .00210 2,100,000 25/32 .7812 19.844 31.87
- .0394 1.000 .00407 1,210,000 - .7874 20.000 32.63
3/64 .0469 1.190 .00688 695,000 13/16 .8125 20.637 35.85
- .0472 1.200 .00704 676,700 - .8268 21.000 37.77
- .0590 1.500 .01377 347,000 27/32 .8437 21.431 40.15
1/16 .0625 1.588 .01632 289,000 - .8661 22.000 43.43
5/64 .0781 1.984 .03187 151,000 7/8 .8750 22.225 44.78
- .0787 2.000 .0326 146,000 - .9055 23.000 49.63
3/32 .0937 2.381 .0550 87,000 29/32 .9062 23.019 49.75
- .0984 2.500 .0638 75,500 15/16 .9375 23.812 55.07
7/64 .1094 2.778 .0875 55,000 - .9449 24.000 56.39
- .1181 3.000 .1101 43,000 31/32 .9687 24.606 60.77
1/8 .1250 3.175 .1305 37,000 - .9842 25.000 63.73
- .1378 3.500 .1749 27,200 1 1.0000 25.400 66.84
9/64 .1406 3.572 .1859 25,700 - 1.0236 26.000 71.69
5/32 .1562 3.969 .2550 18,700 1.1/16 1.0625 26.987 80.17
- .1575 4.000 .2610 18,500 - 1.1024 28.000 89.54
11/64 .1719 4.366 .3394 14,300 1.1/8 1.1250 28.575 95.17
- .1772 4.500 .3716 13,000 - 1.1811 30.000 110.10
3/16 .1875 4.762 .4406 10,700 1.3/16 1.1875 30.162 111.90
- .1968 5.000 .5099 9,500 1.1/4 1.2500 31.750 130.50
- .2165 5.500 .6786 7,150 - 1.2598 32.000 133.70
7/32 .2187 5.556 .6996 6,800 1.5/16 1.3125 33.337 151.10
15/64 .2344 5.953 .8605 5,450 - 1.3386 34.000 160.30
- .2362 6.000 .8810 5,400 1.3/8 1.3750 34.925 173.80
1/4 .2500 6.350 1.044 4,550 - 1.3780 35.000 174.90
- .2559 6.500 1.120 4,300 - 1.4173 36.000 190.30
17/64 .2656 6.747 1.253 3,800 1.7/16 1.4375 36.512 198.50
- .2756 7.000 1.399 3,400 - 1.4960 38.000 223.80
9/32 .2812 7.144 1.487 3,250 1.1/2

1.5000

38.100 225.60
- .2953 7.500 1.721 2,800 1.9/16 1.5625 39.687 255.00
19/64 .2969 7.541 1.749 2,750 - 1.5748 40.000 261.00
5/16 .3125 7.938 2.040 2,350 1.5/8 1.6250 41.275 286.80
- .3150 8.000 2.088 2,150 1.11/16 1.6875 42.862 321.20
- .3346 8.500 2.505 1,900 1.3/4 1.7500

44.450

358.20
11/32 .3437 8.731 2.715 1,750 - 1.7716 45.000 371.70
- .3543 9.000 2.973 1,600 1.13/16 1.8125 46.037 398.00
23/64 .3594 9.128 3.102 1,480 1.7/8 1.8750 47.625 440.60
- .3740 9.500 3.497 1,350 1.15/16 1.9375 49.212 486.10
3/8 .3750 9.525 3.525 1,300 - 1.9685 50.000 509.90
25/64 .3906 9.922 3.983 1,150 2 2.000 50.800 534.70
- .3937 10.000 4.079 1,125 2.1/8 2.1250 53.975 641.40
13/32 .4062 10.319 4.481 1,050 - 2.1653 55.000 678.60
- .4331 11.000 5.429 820 2.1/4 2.2500 57.150 761.30
7/16 .4375 11.112 5.597 810 - 2.3622 60.000 881.00
- .4528 11.500 6.203 720 2.3/8 2.3750 60.325 895.40
29/64 .4531 11.590 6.219 720 2.1/2 2.5000 63.500 1044.40
15/32 .4687 11.906 6.884 620 - 2.5590 65.000 1120.10
- .4724 12.000 7.048 615 2.5/8 2.6250 66.675 1209.00
31/64 .4844 12.303 7.596 610 2.3/4 2.7500 69.850 1390.10
1/2 .5000 12.700 8.355 550 - 2.7559 70.000 1484.70
- .5118 13.000 8.961 490 2.7/8 2.8750 73.025 1588.40
17/32 .5312 13.494 10.02 450 - 2.9528 75.000 1720.70
- .5512 14.000 11.19 410 3 3.000 76.200 1804.70
9/16 .5625 14.288 11.90 380 3.1/8 3.1250 79.375 2039.80
- .5905 15.000 13.77 325 - 3.1500 80.000 2088.30
19/32 .5937 15.081 13.99 320 3.1/4 3.2500 82.550 2294.40
5/8 .6250 15.875 16.32 300 - 3.3464 85.000 2530.90
- .6299 16.000 16.70 275 3.1/2 3.5000 88.900 2865.70
21/32 .6562 16.669 18.89 240 - 3.5433 90.000 2993.40
- .6693 17.000 20.04 230 - 3.7401 95.000 3521.10
11/16 .6785 17.462 21.72 205 3.3/4 3.7500 95.250 3524.70
- .7087 18.000 23.79 190 - 3.9370 100.000 4078.80
23/32 27187 18.256 24.82 180 4 4.000 101.600 4277.70

The weights shown are based on Chrome Alloy Steel balls.
Approximate weights for other materials can be obtained by multiplying the weight per 1000 balls by the following figures:-

Carbon Steel
1.004
Stainless Steel AISI 420/440
0.979
Stainless Steel AISI 302/304
1.011
Stainless Steel AISI 316
1.025
Brass
1.074
Tungsten Carbide
1.907