John deere parts catalog 2787, grid a15, section 20, page 5-engine key 11
No other part numbers with same form, fit, and function found.
A relatively thin metallic item, having a concave or cupped contour, designed to effect its own seal by compression against the circumference of a hole. It is used as a blowout plug in boilers, engines, and the like to relieve the pressure created by the expansion of fluids caused by heat or freezing.
Classification: Parts for steam or other vapor generating boilers and super-heated water boilers, except heat exchangers
NSN 5925-01-287-0657
NSN 5960-01-539-1956
NSN 5920-00-135-4930
NSN 5835-00-190-3401
NSN 6620-00-628-2150
NSN 5855-01-020-7982
NSN 5975-01-265-5122
NSN 6105-00-068-7797
NSN 6150-01-412-7451
NSN 6685-01-206-4945
NSN 5965-00-314-5303
NSN 5998-01-396-9793