RE: [CR]Re-Drilled or pierced


Example: Component Manufacturers:Chater-Lea

From: "David Bilenkey" <dbilenkey@sympatico.ca>
To: <classicrendezvous@bikelist.org>
Subject: RE: [CR]Re-Drilled or pierced
Date: Tue, 1 Jun 2004 19:50:06 -0400
In-Reply-To: <4.2.0.58.20040602090124.009a4250@mailhost.civag.unimelb.edu.au>


Just to concur with Geoff, these would have been punched not pierced. Piercing would not remove metal, just push it aside and create a shaped hole that had more depth (think of pushing a sharp pencil through a piece of paper or thin plastic). The shape of the holes in the brake lever are consistent with a flat punching that has then been formed into the rounded lever. After that the lever would have been cleaned up and then anodized.

David

--- David Bilenkey Industrial Designer Ottawa, Ontario, Canada dbilenkey@sympatico.ca


> -----Original Message-----
> From: classicrendezvous-bounces@bikelist.org
> [mailto:classicrendezvous-bounces@bikelist.org]On Behalf Of Geoff Duke
> Sent: June 1, 2004 7:22 PM
> To: classicrendezvous@bikelist.org
> Subject: [CR]Re-Drilled or pierced
>
>
> Dave Baseley wrote
> "I had heard that the holes ( in SR brake levers ) were pierced
> rather than
> drilled which I took to mean that the holes were done while the material
> was at an elevated temperature"
> While I can't comment on the metallurgical consequences of doing it this
> way in my mind it is more than likely that your informant meant that the
> holes were punched.In my experience with the making of press tools, the
> undeveloped shape of the brake lever along with any holes that
> the finished
> part will contain would be punched out.Sometimes this is done in a number
> of different operations or stages in the same tool.The resultant
> flat piece
> of aluminium is then formed into the required shape.Sometimes, but not
> always in yet another tool.Depending on the depth of forming
> required then
> this may also take place over a couple of stages in order not to stretch
> the material too far in one go and crack it.Hope this helps
> Geoff Duke in Wintery wet Melbourne Australia