2" x 4" SERIES HEAVY DUTY DISC

Specifications
A diam
Max
Weight
Act. Rad.
WR2
Single Stop Energy Absorb.
inch mm RPM lbs Kgs Ft m lb-ft2 kg-m2 hp-sec KJ
18 457 3070 74 34 0.58 0.18 24 1.01 6700 5000
20 508 2750 86 39 0.67 0.20 35 1.47 7800 5800
25 635 2200 118 54 0.88 0.27 78 3.29 9600 7200
30 762 1800 165 75 1.08 0.33 163 6.87 12660 9400
35 889 1550 212 96 1.29 0.39 291 12.26 15000 11200
40 1016 1350 263 119 1.50 0.46 470 19.81 16800 12500
45 1143 1200 302 137 1.71 0.52 693 29.20 179001 13300
50 1270 1070 358 162 1.92 0.58 1040 43.83 20600 15400

B max diam
Max
Weight
Act. Rad.
WR2
Single Stop Energy Absorb.
inch mm RPM lbs Kgs Ft m lb-ft2 kg-m2 hp-sec KJ
7 178 3070 74 34 0.58 0.18 24 1.01 6700 5000
9 229 2750 86 39 0.67 0.20 35 1.47 7800 5800
14 356 220 118 54 0.88 0.27 78 3.29 9600 7200
19 483 1800 165 75 1.08 0.33 163 6.87 12660 9400
24 610 1550 212 96 1.29 0.39 291 12.26 1500 11200
29 737 1350 263 119 1.50 0.46 470 19.81 16800 12500
34 864 1200 302 137 1.71 0.52 693 29.20 17900 13300
39 991 1070 358 162 1.92 0.58 1040 43.83 20600 15400

C min diam
Max
Weight
Act. Rad.
WR2
Single Stop Energy Absorb.
inch mm RPM lbs Kgs Ft m lb-ft2 kg-m2 hp-sec KJ
3.25 83 3070 74 34 0.58 0.18 24 1.01 6700 5000
4 102 2750 86 39 0.67 0.20 35 1.47 7800 5800
3.5 89 2200 118 54 0.88 0.27 78 3.29 9600 7200
4.5 114 1800 165 75 1.08 0.33 163 6.87 12660 9400
5.5 140 1550 212 96 1.29 0.39 291 12.26 1500 11200
6 152 1350 263 119 1.50 0.46 470 19.81 16800 12500
8.25 210 1200 302 137 1.71 0.52 693 29.20 17900 1330
10.25 260 1070 358 162 1.92 0.58 1040 43.83 20600 15400

D max diam
Max
Weight
Act. Rad.
WR2
Single Stop Energy Absorb.
inch mm RPM lbs Kgs Ft m lb-ft2 kg-m2 hp-sec KJ
7.75 197 3070 74 34 0.58 0.18 24 1.01 6700 5000
9.75 248 2750 86 39 0.67 0.20 35 1.47 7800 5800
9.75 248 2200 118 54 0.88 0.27 78 3.29 9600 7200
13 330 1800 165 75 1.08 0.33 163 6.87 12660 9400
13.75 349 1550 212 96 1.29 0.39 291 12.26 1500 11200
15 381 1350 263 119 1.50 0.46 470 19.81 16800 12500
15.75 400 1200 302 137 1.71 0.52 693 29.20 17900 13300
19.5 495 1070 358 162 1.92 0.58 1040 43.83 20600 15400

Note: WR2 and Weight may vary due to machining.


The graph below indicates the horsepower handling capacity of the brake discs in relation to various RPMS.  Please note that the horsepower capacity drastically increases when the disc goes from laminar to turbulent flow.  The energy indicated is based on a continuous input with a maximum disc temperature of 600oF (315oC) and does not require any stopping or brake release time.  It is important to remember that disc brake installations running on continuous power input should not exceed 700oF (370oC) disc temperature.
Graph HP vs RPM
MAXIMUM ENERGY CAPACITY FOR A SINGLE STOP FROM CRITICAL RPM (LAMINAR FLOW)
Maximum Temperature 700oF (370oC)
Disc
Critical rpm
1 sec
2 sec
5 sec
hp-sec
kJ
hp-sec
kJ
jp-sec
kJ
2x4x18 740 2340 1740 3315 2470 5240 3910
2x4x20 620 2800 2090 3960 2950 6260 4670
2x4x25 480 3690 2750 5220 3890 8250 6150
2x4x30 380 4580 3420 6475 4830 10240 7640
2x4x35 320 5470 4080 7735 5770 12230 9120
2x4x40 280 6360 4740 8990 6700 14215 10600
2x4x45 200 7250 5410 10250 7640 16200 12080
2x4x50 210 8135 6070 11505 8580 18190 13560

MAXIMUM ENERGY CAPACITY FOR A SINGLE STOP FROM CRITICAL RPM (LAMINAR FLOW)
Maximum Temperature 700oF (370oC)
Disc
Critical rpm
10 sec
30 sec
1 min
hp-sec
kJ
hp-sec
kJ
jp-sec
kJ
2x4x18 740 6730 5020 6865 5120 7075 5280
2x4x20 620 7775 5800 7900 5890 8080 6030
2x4x25 480 9645 7190 9820 7320 10085 7520
2x4x30 380 12590 9390 12780 9530 13085 9760
2x4x35 320 1500 11190 15225 11350 15590 11630
2x4x40 280 16845 12560 17130 12770 17580 13110
2x4x45 200 17895 13340 18200 13570 18660 13910
2x4x50 210 20600 15360 20980 15640 21570 16080

MAXIMUM ENERGY CAPACITY FOR A SINGLE STOP FROM CRITICAL RPM (LAMINAR FLOW)
Maximum Temperature 700oF (370oC)
Disc
Critical rpm
2 min
5 min
10 min
hp-sec
kJ
hp-sec
kJ
jp-sec
kJ
2x4x18 740 7500 5590 8850 6600 11060 8250
2x4x20 620 8460 6310 9590 7150 11385 8490
2x4x25 480 10635 7930 12230 9120 14905 11110
2x4x30 380 13720 10230 15580 11620 18585 13860
2x4x35 320 16340 12180 18570 13850 22170 16530
2x4x40 280 18510 13800 21240 15840 25780 19220
2x4x45 200 19610 14620 22300 16630 26810 19990
2x4x50 210 22790 16690 26280 19600 32270 24060

The calculations indicating disc temperature or energy capability are based on the rubbing face and the find of the disc only.  The mounting flange of the disc and the rotating element that the disc is attached to are not considered in our calculations.  Also in air flow we have allowed for some restrictions because normally guards and obstructions are imposed to the air flow in most instances.  Because of this, in many cases up to three times more energy can be absorbed by the disc, but since all of these items are unknown to us, we feel that we must offer the utmost in security, as far as brake performance  is concerned.  If specific details are available of your brake installation, we will be please to do a computer run and give you precise performance criterias.

If a brake disc and brake caliper are properly selected, many years of trouble-free service can be expected.  Early disc failure can occur if for example a disc cycles continuously, and goes from extremely hot to cold conditions constantly, (metal fatigue).  Because of these constant thermo-stresses, heat checks will occur and major cracks will appear after some time of operation.  If a brake disc and brake caliper are properly selected, this can all be avoided.

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