Fitting a buckle – Tips

Written on 11 Apr 2015

IMG_3188 copyFitting a buckle to a leather strap.

Note: This is not intended to be a full ‘how to’ rather, it is for those who have fitted a buckle before but need some tips as a reminder. Look carefully at the buckle parts before working through the tips that follow.

Establishing the correct strap width:

Measuring a buckle to fit a leather belt or strap

Measuring the inside width of the buckle bar


The leather strap should be the same width as the inside width of the buckle. To establish the width of the buckle in mm or inches, measure the inside width of the buckle along the bar that the prong is fitted to. Adjust the strap cutter to this measurement and test on some scrap leather before cutting a whole strap length.  See our videos for how to set and use the wooden strap cutter.

Run a ‘buckle fitting’ test first:

Image showing leather strap is too wide for buckle

Leather strap is too wide for the buckle

Image showing that leather strap is too narrow for buckle

Leather strap is too narrow

Feed the leather strap through the buckle to check that it’s a really good fit.  If the leather is forced upwards on one side of the buckle then the strap is too wide and if you can see gaps between the leather and the inner side edges of the buckle, the strap is too narrow.  If necessary cut another test piece.

The tricky bit:

Measuring for the slot length

…then measure the string to determine the required length of the slot

Measuring a buckle prong

Use string to measure the curve of the prong…

Using a flexible tape or piece of string, measure the curved section of the prong only (see picture).  This measurement will be the length of the slot needed for that curve of the prong to sit in. This needs to be a snug fit – if it’s too short the curved section of the prong will be hidden,either partially or fully and will cause a bulge to form.  If it’s too long then a gap will be visible at one, or both ends of the slot.  Punch through making sure that the slot is straight not angled, as this will cause the buckle to ‘twist’.

The ‘turnover’ allowance:

IMG_8079 copy-resized-1024pxIMG_8076 copy-resized-1024pxIMG_8077 copy-resized-1024px

 Now decide where the buckle will be positioned on the strap.  It is usually 1 1/2″ – 2 1/2″  from the end of the strap – this is where the leather will fold into a ‘turnover’ so mark a centre point with the scratch awl for reference.  A slot running lengthways will need to be cut at this measurement to allow the curved section of the buckle prong to sit in – this is the bit of metal that wraps, or curves around the buckle bar thus allowing it to move freely.

Nearly there…

IMG_8082 copy-resized-1024pxWet or dampen the leather turnover section before gently folding, to avoid causing the leather to crack. Attach the buckle making sure that the leather lays flat on the bar as well as sitting snugly within the buckle’s inside edges. Mark a line on the flesh side of the leather strap with the scratch awl, where the turnover is to stop.

Now for the real thing:

Using the crew punch to fit a buckle to a leather strap

Using the slot (or crew) punch

When you’re satisfied with the result of your test piece you’re ready to cut out the full length of your strap.  By now you will already have the strap cutter set to the correct width for your buckle and you will also have established which size slot punch to use.

Don’t forget to:

Edge shave
Mark your stitch lines
Use the pricking iron
Sand the flesh side of the whole turnover before gluing to ensure a good ‘stick’.
Make your keeper beforehand, if needed.
Shape the belt or strap tip
Edge dye and burnish.


Remember that the prong determines the size of the nine or seven holes. For a neat finish these holes should be spaced evenly apart and should also be positioned centrally across the width of the strap or belt.

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