Circlips- how to measure

Kelpie

Kelpie

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I'm rebuilding a roller furler and would like to replace the old circlips with stainless ones while I've got it apart.
Only question is, how do I correctly measure the sizes?
E.g. for one component, the circlip fits over a 40mm diameter shaft. The groove that it fits in to measures about 38mm diameter. So which one of these two measurements is the one I need for the circlip? Likewise there is a housing 52mm internal diameter, the circlips that fit in to the wall of this need to expand to 55mm diameter.

I did try emailing a supplier but no response.
 
Daverw said:
External circlips measure OD of groove, internal circlips measure ID of groove. It’s the bit that sits metal to metal that matters.
Click to expand...
Are you sure ?

ITYWF that a nominal 40mm external clip fits a 40mm shaft. The groove will be 37.6mm diameter and the relaxed (internal) diameter of the clip will be 36.5mm


and that a nominal 52 mm internal clip fits a 52mm bore housing. The groove will be 55mm diameter and the relaxed ( external ) diameter of the clip will be 56.2mm
 
VicS said:
Are you sure ?

ITYWF that a nominal 40mm external clip fits a 40mm shaft. The groove will be 37.6mm diameter and the relaxed (internal) diameter of the clip will be 36.5mm


and that a nominal 52 mm internal clip fits a 52mm bore housing. The groove will be 55mm diameter and the relaxed ( external ) diameter of the clip will be 56.2mm
Click to expand...

Vic is correct, it's shaft size or bore size that matters.
 
Happy to be corrected, in our factory stores we always used the groove dimension but that may have just been how our storesman did it, we were not using standard parts though
 
VicS said:
Are you sure ?

ITYWF that a nominal 40mm external clip fits a 40mm shaft. The groove will be 37.6mm diameter and the relaxed (internal) diameter of the clip will be 36.5mm


and that a nominal 52 mm internal clip fits a 52mm bore housing. The groove will be 55mm diameter and the relaxed ( external ) diameter of the clip will be 56.2mm
Click to expand...
That doesn't seem to make sense. The circlip will be most effective if its ID will exactly match the groove OD otherwise it isn't making best effective contact over its surface.

External Circlip Dimensions for Shafts (Metric)
is heavy going but the example shown cites a 10 mm diameter shaft, a groove diameter of 9.6 and an internal circlip diameter of 9.2.

Apparently , am alternative name for a circle is a "Jesus clip" which derives comes from the propensity of the clip's spring action to launch the clip at a high velocity when removing or installing, leading to remarks such as, "Oh Jesus, where did it go?"
 
I had circlips on our old Jabsco loo some years ago. I got tired of the clips rusting and replaced them with stainless. These all failed after very short use. It may have been a quality issue but I am now wary of them.
 
Kelpie said:
I'm rebuilding a roller furler and would like to replace the old circlips with stainless ones while I've got it apart.
Only question is, how do I correctly measure the sizes?
E.g. for one component, the circlip fits over a 40mm diameter shaft. The groove that it fits in to measures about 38mm diameter. So which one of these two measurements is the one I need for the circlip? Likewise there is a housing 52mm internal diameter, the circlips that fit in to the wall of this need to expand to 55mm diameter.

I did try emailing a supplier but no response.
Click to expand...
I find you get a better response from people if you actually talk to them. An email often means it's been sent to several recipients. Also emails are easily misunderstood.
Try Spring masters in Redditch, they've been making them for generations
 
Graham_Wright said:
That doesn't seem to make sense. The circlip will be most effective if its ID will exactly match the groove OD otherwise it isn't making best effective contact over its surface.

External Circlip Dimensions for Shafts (Metric)
is heavy going but the example shown cites a 10 mm diameter shaft, a groove diameter of 9.6 and an internal circlip diameter of 9.2.

Apparently , am alternative name for a circle is a "Jesus clip" which derives comes from the propensity of the clip's spring action to launch the clip at a high velocity when removing or installing, leading to remarks such as, "Oh Jesus, where did it go?"
Click to expand...
The clip is supposed to be under tension when fitted, so that it doesn't tend to move and hence wear.
Also, to resist 'strong centrifugal force' according to Springmasters.
 
Graham_Wright said:
That doesn't seem to make sense. The circlip will be most effective if its ID will exactly match the groove OD otherwise it isn't making best effective contact over its surface.
Click to expand...
I did not make up the numbers.
I copied them from a table of dimensions for DIN 471 and DIN 472 circlips

I get the same if I use the calculator on the site you provide the link for
 
Graham_Wright said:
That doesn't seem to make sense. The circlip will be most effective if its ID will exactly match the groove OD otherwise it isn't making best effective contact over its surface...…
Click to expand...

There's enough "spring" in a circlip to match variations in diameter, it will still make proper contact around the circumference.
 
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