Die Casting Thread

Dear sir,

Basicaly Iam from forging line ,I do not know much about die casting. But ,I found your question very intrsting. You have not spcified which standard and type of thread you mean. I think for any type of thraeds you have notic or take in conideration it's basic dinensions and tolrances intened in work piece and its gauge dimension and tolerances and layer on intended chromplating or powder coating and its quality to sevrv your end use /pupose acoordingly for internal threads you havekeep thread dimension to apropriate plus side and for external minus side, so after coating it shuold be the same dimensions specified in standard andit shoul be checked by gauged 'go'-'no go'.

Let me also know ,if you get very apropriate answer, I am interested to know

Thank you.

V.D.DEODHAR.

This can be done. It is however not commonly done as there are so many things that can go wrong that then require re-working to make then right.

A common way to avoid the problem is to produce the threaded component as an insert that is placed in the die and then cast the item around the insert.

This avoids the problems with expansion and contraction due to the heat of the molten metal and the problems of chilling in the threaded area giving an incomplete thread.

You have not indicated your proposed thread form or the metal you intend to cast.

Cheat and use an insert. This could also be pre-chromed to avoid the difficulty of partial chroming of a completed item.

BAB.

Thanks for all of your input here. Currently I use inserts for two kinds of finish. My question is: how to define thread spec for major diameter and pitch diamter for casting? For examples, I am asked to make M22*1.5 -6g thread by casting, what is the major dia and pitch dia for casting? What is the major dia and pitch dia as finished?

Thank all of you!

Finished

Effective Dia for M22x1,5-6g = 20,994 max 20,854 min.

Outside Dia 21,968 max 21,732 min

Core Dia 20,128 max 19,890 min

Hi Fisher Yu

You need to apply Bolt Thread Tolerance "e" DIN13 which allows for a surface protection coating of your choice and to end up with a component complying to Bolt thread tol "g"

Measure the effective dia over wires using the formula for Metric thread: 2b = 3d-0,8660P. Where M = Effective dia + 2B

d = Measuring wire dia.

M = Measured value over wires

Best wire dia to utilise = .57735P