Re: Small Part Machining

D D PALMER

June 30, 2011 at 10:46 AM

Ouch!

Score another one to the advatages of "numb junk" argument.

From: sygibson@gmail.com
Date: Thu, 30 Jun 2011 10:08:20 -0700
To: obra@list.obra.org
Subject: Re: [OBRA Chat] Small Part Machining

I agree with what Jon says. I've broken a seat bolt in the past (during rather rigorous mountain biking ... and the results ... were very, very painful). I searched high and low for a replacement bolt - and found that Chown Hardware in Portland, on SE Stark carries a very very wide selection of high quality bolts. I rode using that replacement bolt from Chown for 5 more years of hard use before retiring that bike.

You do NOT want your seat bolt to break at the wrong time. Trust me.

~~shane
--
"Opportunities multiply as they are seized." - Sun Tzu

On Thu, Jun 30, 2011 at 9:26 AM, Jon Myers wrote:

I would be very careful picking the material for this part. The parts around the seat post tend to be very highly stressed. Often these parts are a high strength alloy steel. These parts are typically machined in an annealed condition when it is softer and easier to machine. Then the part is then heat treated to give it a good mix of hardness, strength and ductility. A steel part that is heat treated to full hard can be up to 4 times as strong as the same part in an annealed (soft) condition.
-Jon
_______________________________________________
OBRA mailing list
obra@list.obra.org
http://list.obra.org/mailman/listinfo/obra
Unsubscribe: obra-unsubscribe@list.obra.org

_______________________________________________ OBRA mailing list obra@list.obra.org http://list.obra.org/mailman/listinfo/obra Unsubscribe: obra-unsubscribe@list.obra.org