can someone please help with hole dimensions

[reefy86]

so just to double check. if i make holes in my drawing thats 4.5mm and send that drawing of to be drilled will they tap my holes at 4.5mm or will they just do a basic straight hole at 4.5mm?

cheers

Ash

[komatias]

depends if you send them a drawing or a solid model. As a rule, you should not send a solid model without a drawing to ensure your intentions are met. For example, a solid model may not convey tolernaces.

A 4.5mm hole is just that. Unless you tell them to tap it to an M4, you will not get at tapped hole. Also worth noting that if you can accept a drilled hole, make a note that the drill point is acceptable. Flat bottomed holes are marginally more expensive.

[reefy86]

thing is though that really confuses me is when looking at the dimensions from zapp it just shows a diagram with an hole at 4.5mm, im not good at knowing what holes what but in solidwork i select m4 and it has a default settings at 10.10mm blind hole depth and 8.00mm tap thread depth.

[komatias]

Slightly confused myself here too. What are you trying to draw up, the rail or the mating part?

If it is the mating part:
That setting is fine if you want a threaded hole. It give you two full diameters worth of M4 thread. I am sure you know you cannot tap to the bottom of a blind hole so the 10.10 is pretty decent in my mind.

[Clive S]

thing is though that really confuses me is when looking at the dimensions from zapp it just shows a diagram with an hole at 4.5mm, im not good at knowing what holes what but in solidwork i select m4 and it has a default settings at 10.10mm blind hole depth and 8.00mm tap thread depth.

As have been said A 2D drawing is best and if you are asking for holes to bolt the rails to, through holes are much easier to drill and tap. As long as the hole centres are marked and dimensioned on the drawing that will be fine. You can just say drill for M4 or M5 or whatever size you want, the company would then drill the appropriate hole.

[reefy86]

forgive me for sounding dumb, so if i ask them to make an m4 hole will they know to tap it or will i have to tell them.

[reefy86]

its for the linear profile rails.

[komatias]

Never assume that the machine shop knows what you mean or need. You can however be as descriptive as you want. For example, you add an arrow to the threaded whole with a note leading from it saying: 24 X M4x0.7 8mm MIN FULL THREAD. DRILL POINT OPTIONAL TO DEPTH 12MM

[reefy86]

thank you :)