Two different types of MS21045-6 3/8-inch locknuts?

[rv12iS-builder]

Are there two different styles of MS21045-6 3/8-inch locknuts? Van’s sent me one nut that looks like the nut on the left and three that look like the nut on the right. I’m familiar with the locknut on the left, but not the one on the right. Can these be used interchangeably? Four nuts are used to attach the WD-1220 engine mount ring to the RV-12IS fuselage, and I want to be sure that both styles are acceptable and can be used together for this application. Thanks!

 

[RVDan]

The Mil Spec shows 2 styles, one with the segmented locking device and one with a non segmented elliptical device. The segmented style is type A and the elliptical one is type B. Interchangeable.

 

[rv12iS-builder]

The Mil Spec shows 2 styles, one with the segmented locking device and one with a non segmented elliptical device. The segmented style is type A and the elliptical one is type B. Interchangeable.

Thanks, Dan! There's always more to learn!

 

[cvairwerks]

Thanks, Dan! There's always more to learn!

Mark: Everyspec.com is one of the places that has most of the specification for parts that we use, and it's free. A few weeks back, there was mention of a company that has a printed hardware reference manual that is free. It may take a few weeks or a month or two to get a copy, and if you order one, be sure to support them and their effort. The company is General Aircraft Hardware and is based in Billings Mt. BTW, they are phasing out the website and for now at least, will be facebook only.

 

[rv12iS-builder]

Mark: Everyspec.com is one of the places that has most of the specification for parts that we use, and it's free. A few weeks back, there was mention of a company that has a printed hardware reference manual that is free. It may take a few weeks or a month or two to get a copy, and if you order one, be sure to support them and their effort. The company is General Aircraft Hardware and is based in Billings Mt. BTW, they are phasing out the website and for now at least, will be facebook only.

Thanks, cvairwerks!

 

[rbibb]

Are there two different styles of MS21045-6 3/8-inch locknuts? Van’s sent me one nut that looks like the nut on the left and three that look like the nut on the right. I’m familiar with the locknut on the left, but not the one on the right. Can these be used interchangeably? Four nuts are used to attach the WD-1220 engine mount ring to the RV-12IS fuselage, and I want to be sure that both styles are acceptable and can be used together for this application. Thanks!

View attachment 94853

Attached spec explains all the variations....

 

[rv12iS-builder]

Attached spec explains all the variations....

Thanks, Richard! Very helpful!