Roll/spring pins

[raptrbreth]

I searched here and google but didn't find the answer. Is there a difference in application of a roll pin and a coil pin (looks like a jelly roll)? Different part kits come with different style pins and the coil pin seems to be much easier to install. Will it even matter for any application in the AR?

 

[churchmouse]

Roll pins are supposed to be tight. They stay put that way. If it was designed for a roll pin I use one.

 

[Robert Richardson]

Roll pins are straight, spring pins are tapered for easy installation. If it calls for a roll pin, use a roll pin, as CM stated, they are stronger and tighter.

 

[raptrbreth]

What I meant is the difference between this one

And this one

I have seen both kinds in kits. Is there a difference in application?

 

[Gaffer]

I was curious myself, and found this article on Wikipedia.

https://en.wikipedia.org/wiki/Spring_pin

Ron

 

[churchmouse]

What I meant is the difference between this one
View attachment 57256
And this one
View attachment 57257
I have seen both kinds in kits. Is there a difference in application?

I am familiar with these pins but never seen any in an AR parts kit.

 

[CountryBoy19]

What I meant is the difference between this one
View attachment 57256
And this one
View attachment 57257
I have seen both kinds in kits. Is there a difference in application?

Just to clear up terminology, the top is a spring-pin (it's hardened spring steel and is over-sized so it "springs" against the hole), the bottom is a roll-pin (it's nothing but a rolled up bit of steel).

As far as shear strength it depends entirely on the actual pin itself (not just the type of pin), as far as retention, when installed they are both supposed to be equal. However, I've found that many roll-pins are made super cheap these days and that spring pins are more consistent. I would rather have a spring pin.