Details
This is the most common type of key, if in doubt choose this style. Available in sizes 00 to 13.
Not sure which size? Measure the edge of the winding peg and click here for a conversion chart.
QUESTIONS & ANSWERS
Ask a Question- 
         
I have a 50s smths mantel clock with Westminster chime I don't know the size of key can you help
Measure the winding pen (the little square peg the key fits over) and use our conversion chart to see which size you need.
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I have bought a 4mm brass clock key (like yours with butterfly handle) from another supplier but it is too small. Difficult to get exact measurement as spindle is slightly below level of face. If I order size 8 from you (4.25mm) and it is still too small can I return for a 4.5mm? Thanks.
Yes.
And return postage is free.
(Consider buying all your clock tools from Quicktest!) 
              
              
    
      
      
      

