4 mm OD shaft, 30 mm long with 0.5 mm bore
4 mm OD shaft, 30 mm long with 0.5 mm bore
(OP)
I am in need of a 4 mm stainless steel shaft with a center hole of 0.5 mm. I need to fabricate about 100 parts of 4 mm diameter, 30 mm long with o-ring grooves, taper geometries and a center hole of 0.5 mm. While most of the features are doable in a CNC lathe , I think the hole cannot be drilled. Does anyone know where I could find stock material with the hole already there?





RE: 4 mm OD shaft, 30 mm long with 0.5 mm bore
RE: 4 mm OD shaft, 30 mm long with 0.5 mm bore
RE: 4 mm OD shaft, 30 mm long with 0.5 mm bore
http://www.connhypo.com/pages/sub05_toc01.html
Looks like 6 gauge is ~ 5 mm OD, so your size fits within their capabilities.
RE: 4 mm OD shaft, 30 mm long with 0.5 mm bore
A .5 mm hole 30 mm long is an aspect ratio of 60. I think only ram EDM or lasers can drill something like that and it's going to be slow and expensive.
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RE: 4 mm OD shaft, 30 mm long with 0.5 mm bore
It looks like you have a ratio : Length/ID >10, which means that drilling is very difficult or impossible, in you case L/D=60...
Can you please load a PDF file with tolerances, it will be easier to suggest a process?
What stainless grade are you looking for?
Are you looking for higher volume, in the future?
here are some Ref. ,
http://www.forecreu.com/
http://www.smt.sandvik.com/bioline
http://www.nesmalltube.com/
Regards,
RE: 4 mm OD shaft, 30 mm long with 0.5 mm bore
Mike Halloran
Pembroke Pines, FL, USA
RE: 4 mm OD shaft, 30 mm long with 0.5 mm bore
Dgallup, I have thought of EDM as a last resort if I find nothing else but yeah, I think its going to push production costs through the roof :(
I am not familiar with the laser technology that can create such a hole, what do you have in mind?
Zinov, ideally I would like to use 316 surgical steel. My pdf drawing is not updated but my tolerances are +/- 0.05 mm for the hole and 0.1 mm for everything else.This is a prototype so, yeah, hopefully I will be looking for higher volumes in the future.
MikeHalloran, thanks, I never thought of that. Is this how needles are made? One would need to design special tooling for that kind of process? Could I get that 0.05 mm tolerance for the hole like that or is it unlikely?
RE: 4 mm OD shaft, 30 mm long with 0.5 mm bore
RE: 4 mm OD shaft, 30 mm long with 0.5 mm bore
Buy a thick cylinder stiff enough to be drilled: though that is difficult with this small a hole. Assume your can get a drill through at 12 mm dia, maybe 16 mm of stock.
Drill through the 20mm blank, but don't try to get that hole centered "perfectly". Instead, after drilling the 0.5 mm hole first, then use the drilled hole as a center for machining the outside tapers and grooves by the lathe from the outside to match the drilled hole for concentricty.
RE: 4 mm OD shaft, 30 mm long with 0.5 mm bore
Reset the blank so the new hole is on center in the lathe with a true 4.0 mm dia hole.
Then machine the outside down to your final shape.
RE: 4 mm OD shaft, 30 mm long with 0.5 mm bore
RE: 4 mm OD shaft, 30 mm long with 0.5 mm bore
Does the hole need to 0.5 all the way through? Can it be bigger most of the way and step down? Could you start with a piece on tubing and neck it down in sections to restrict the ID?
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The Help for this program was created in Windows Help format, which depends on a feature that isn't included in this version of Windows.
RE: 4 mm OD shaft, 30 mm long with 0.5 mm bore
http://www.metricmetal.com/products/capillary_tubing.htm
RE: 4 mm OD shaft, 30 mm long with 0.5 mm bore
What is the function of the hole? Can it be larger ID and "orificed" at the ends? Interference fit sleeves for short length in both ends to obtain the ID that you want?
To that end, could you use off the shelf 4mm x 1mm tubing that compositepro linked, and sleeve the entire ID? Sleeves could be multiple sections if needed to facilitate the insertion.
RE: 4 mm OD shaft, 30 mm long with 0.5 mm bore
Unfortunately I cannot limit the 0.5 hole to specific areas since there are some o-ring grooves along the shaft that need the extra material to avoid fracture due to excessive stress.
However I found hollow shafts at the diameter I am looking for in http://www.forecreu.com/ that zinov linked, thanks for that!