High Duty Safety Spring Washers

High duty safety spring washers are designed for use as loose washers over screws and bolts. Manufactured to DIN 6796 they are designed to be used for medium or high strength screw or bolt assemblies.

The high supporting load and spring return make the HDS series extremely effective where bolt tension may be subject to relaxation due to such factors as : smoothing out of wear parts, creep, relaxation, thermal expansion or contraction, or compression set of gaskets. The HDS series multiplies the elastic action of the screw. They are an effective replacement for the time honored, but obsolete and ineffective, lock washer / flat washer combinations.

Since the HDS series are disc springs they can be stacked in series and/or in parallel. Series stacking increases the available deflection of the spring stack. Parallel stacking increases the spring force. The desired installation is as near flat as possible. When nearing flat, the tightening torque increases sharply, indicating the proper bolt tension without a torque wrench.

HDS washers, hardened (43-48 Rc), are made of Carbon Spring Steel, larger sizes having machined OD and ID. Other materials are available on request. HDS washers are delivered with blank, slightly oiled surfaces. Phosphate and Zinc plating on request.
High Duty Safety Spring Washer Technical Drawing

Diameter Bolt Size Inch OD Inch ID t H max * H min # F (lb) OD mm ID t H max * H min # F (N) +
M2   0.197 0.087 0.016 0.024 0.020 140 5 2.2 0.40 0.60 0.50 630
M2.5   0.236 0.106 0.020 0.028 0.024 210 6 2.7 0.50 0.72 0.61 950
M3 1/8 .#5 0.276 0.126 0.024 0.033 0.028 300 7 3.2 0.60 0.85 0.72 1,320
M3.5 .#6 0.315 0.146 0.031 0.042 0.036 540 8 3.7 0.80 1.06 0.92 2,400
M4 5/32.#8 0.354 0.169 0.039 0.051 0.044 850 9 4.3 1.00 1.30 1.12 3,800
M5 3/16.#10 0.433 0.209 0.047 0.061 0.053 1,230 11 5.3 1.20 1.55 1.35 5,500
M6 1/4 0.551 0.252 0.059 0.079 0.067 1,930 14 6.4 1.50 2.00 1.70 8,600
M7   0.669 0.291 0.069 0.091 0.079 2,540 17 7.4 1.75 2.30 2.00 11,300
M8 5/16 0.709 0.331 0.079 0.102 0.088 3,360 18 8.4 2.00 2.60 2.24 14,900
M10 3/8 0.906 0.413 0.098 0.126 0.110 4,970 23 10.5 2.50 3.20 2.80 22,100
M12 1/2 1.142 0.512 0.118 0.156 0.135 7,670 29 13.0 3.00 3.95 3.43 34,100
M14 9/16 1.378 0.591 0.138 0.183 0.159 10,340 35 15.0 3.50 4.65 4.04 46,000
M16 5/8 1.535 0.669 0.157 0.207 0.180 13,400 39 17.0 4.00 5.25 4.58 59,700
M18   1.653 0.748 0.177 0.228 0.200 16,700 42 19.0 4.50 5.80 5.08 74,400
M20 3/4 1.772 0.827 0.197 0.252 0.220 21,000 45 21.0 5.00 6.40 5.60 93,200
M22 7/8 1.929 0.906 0.217 0.278 0.242 25,600 49 23.0 5.50 7.05 6.15 114,000
M24   2.205 0.984 0.236 0.305 0.267 29,400 56 25.0 6.00 7.75 6.77 131,000
M27 1 2.362 1.102 0.256 0.329 0.287 34,600 60 28.0 6.50 8.35 7.30 154,000
M30 1 1/8 2.756 1.220 0.276 0.362 0.315 38,700 70 31.0 7.00 9.20 8.00 172,000
FMP Part Number = W096-Diameter-0000 (Bare Steel)
FMP Part Number = W096-Diameter-0000-ZN (Zinc Plated)

( * )Overall height before set out
( # )Overall height after set out
( + )Approx. force to flatten. Twice calculated force at deflection Hmin - S

*All information is strictly informative