[Pharmerphil]

Hi, see attached photo.
Can anyone tell me that these are used for. They came with a used mini-milling machine I purchased.
There are about 125mm (5in) long and are sized from 1mm to 13mm in increments of 0.5 mm.
The tips are not hard enough to be used as a center punch.
Sorry, but I can't figure out how to stop it rotating the photo when I upload it.
Thanks.

[routalot]

They may well be transfer punches and it looks like they have seen some use.The idea is that you lay a pattern on top of the job and after aligning or scribing the edges you slot the appropriate sized transfer punch in the holes in the pattern and tap it with a hammer to give the centre of the hole in the part.The conical tip should leave an indentation for the punch or centre drill to engage with.

[Stan Stocker]

They are transfer punches. Typically you put the punch through a hole on one part, align the part you want a matching hole in, and give a tap to center punch. Often used to let you drill and tap a hole so you can bolt two pieces together. Very handy when mounting things to a large piece, machine, metal building, where drilling the second hole by coordinates just isn't really in the cards, or would be plain silly to try. Ever tried to put a tractor bucket on a mill table? :-)

Cheers, Stan

[deadlykitten]

Ever tried to put a tractor bucket on a mill table? :-)

hy i just remembered that i know how to craft a bucket ... the front has to be wider, so to avoid friction on sides, and there is a back plate, that is being cut not at the begining, but when the bucket is almost done : weldings are leading to deformations, and each bucket may be a bit different, but if some dimensions are measured after almost all weldings had been done, then is possible to custom cut a part (then weld it), in order to make each bucket look perfect

deviations are greater as bucket size increases, and are lower when bending cncs are used ( so to reduce human error when rolling the middle plate )

special fixtures may be used to align the parts before welding, in order to achieve consistent shapes, but is possible to entirely craft a bucket only with a piece of chulk

a small trick to reduce deviations, is to increase clearance between sides and curved plate only arround the middle, thus being sure that contact is achieved only at start & end of contour : this reduces the power of weldings arround the middle, leading to less stress into the final bucket ... also, it requires that the middle big plate, before being rolled, to have not only linear edges, but also arch shapes

... and, in the end, the "ears" are welded, so to be able to mount the bucket on the agricultural equipment; each bucket may be mounted on different equipments, so generally there may be a database with bucket dimensions, and another one with " ears " for different agricultural equipment brands / kindly

[Pharmerphil]

Thanks everyone for the replies. I googled 'transfer punches' and came up with an image of the set I have.