Morris Minor Owners Club

No, not a mistyped religious statement, but a serious question:

There are many situations where a shaft might have a groove near the end into which will sit a clip in order to retain either the shaft or a gear wheel in position. Over the years, I have seen many situations where external circlips or C-Slips are used:
And plenty of others where a E-Clip is fitted instead:
The question I am pondering is whether there is a valid engineering reason for choosing one type over the other, or will either (as long as of the correct size) serve equally well?

Simply put:-
The circlip either internal or external is mostly used in an engineering situation where the item being retained can place a load on the circlip. The circlip fits into either a internal or external machined groove
The 'E' clip is more for the simple retention of an item. It is not for the retention of an item that is subject to loading and can only be used in an external capacity/role. The groove that the 'E' clip fits into does not have to be a specifically machined groove.

simmitc wrote: ↑Tue Jan 31, 2023 2:53 pm No, not a mistyped religious statement, but a serious question:

Very interesting, thank you philthehill for explaining the difference.

I agree with Phil, the E Clip is simply a retainer, probably plated mild steel, which is pushed ON or OFF of a slot in a bar without any special tooling, e.g it can be prised off with a screwdriver, or pushed on while holding in a pair of pliers. They are also only 'external' to a bar or pin.

There are 'E Clip Removal Tools you can buy, but they're basically just slotted flat bar to get under the clip and lever it off... A Circlip, or 'C' Clip is sprung steel, can be internal or external, and to fit/remove properly, requires the use of Circlip Pliers, ones with little pins on the end.


There are some variations on the theme, such as 'Snap Rings' which if I recall correctly are the ones like Circlips but without any holes to use Circlip pliers. basically they just look like a ring that's been cut.

Did you know circlips have front and back? The holes are tapered and the smaller diameter goes to the pliers. The pliers pins are also tapered toward the handles so the pressure to compress or expand the clip pulls onto the pliers rather than flying off Particularly important when ciclip are in deep recesses such as inside gears.
Snap ring pliers have flat serrated faces to provide grip to the snap ring which have no eyes .