GMW GMW17409 PDF

Introduction

Note: Nothing in this standard supercedes applicable laws and regulations.

Note: In the event of conflict between the English and domestic language, the English language shall take precedence. 

Purpose. This procedure evaluates the contact corrosion potential of elastomer seal and O-ring compounds on machined metal surfaces. 

Applicability. 

Test results are compared to five graduated contact corrosion levels shown in Figure 7. A scale rating is assigned that is the closest to the test result.

The desired maximum contact corrosion rating is listed in the relevant GM document/print. A zero or low corrosion (C) number is desired.

Remarks. 

This procedure is primarily intended for crankshaft seals on machined steel shafts. The test is intended to screen compounds in contact with sensitive shaft surfaces that may exhibit high corrosion tendencies. 

Shaft corrosion can lead to surface pitting and progressive loss of effective seal contact to prevent leakage. 

SAE J403 grade 1020 cold roll carbon steel stock is used for its sensitivity to corrosion for a short test period. Actual production shaft materials will provide different results.