FED-STD-791 Lubricants, Liquid Fuels, And Related Products, Testing Method OfThis test method standard is composed of standard test methods for sampling, inspecting and testing lubricants, liquid fuels and related products. It is issued pursuant to the Federal Property and Administration Services Act of 1949, as amended and its application to the purchase of commodities referred to herein is mandatory on all Federal agencies.

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'�NOTE:This draft dated 15 April 2006' by DasH - Page 29 of 460

FED-STD-791D

Method 335.3

September 30, 1986

GEAR WEAR

1. SCOPE

1.1 This method is used for determining the relative lubricity of greases.

2. SUMMARY

2.1 This method consists of lubricating test gears (2 sets) of known wearing quality with

the grease to be tested, running the gears under specified loads, and reporting the wear as the

average loss in weight of the gears.

3. SAMPLE SIZE

3.1 Approximately 1 g of grease to be tested.

4. REFERENCES, STANDARDS, AND APPARATUS

4.1 Gear wear tester (Figure 1), consisting essentially of:

a. Drive shaft, including 2.54-cm (1-in) O.D. drive pulley and provision for

mounting a brass test gear (see Figure 2).

b. Driven shaft, including 2.54-cm (1-in) O.D. loading weight pulley and provision

for mounting a steel gear (see Figure 2).

4.2 Drive mechanism, reciprocating (sinusoidal linear motion), 7.98 cm (3.14 in)

amplitude, 60 CPM, with a cycle counter (6000 cycles minimum).

4.3 Weight, 2.27 kg (5 lb) (see Figure 1).

4.4 Weight, 4.54 kg (10 lb) (see Figure 1).

4.5 Brush, stiff-bristle (toothbrush or equal).

4.6 Oven, 71�C (160�F).

4.7 Balance, sensitivity 0.1 mg.

4.8 Container (for holding di-2-ethylhexylsebacate in contact with steel gear).