Work Hardened Gunmetal

[ken heppenerParticipant @kenheppener64998]

Hi All….I seem to be having a problem with drilling the mounting plate where my regulator water pump will fit on the boiler side…..I made a template for ease of drilling for the 5BA thread but my drill will not cut into the gunmetal….My only guess is that when the boiler was made the high temparature used has hardened the metal…..Any idea how I can get arround this problem as I’m at a loss  of what to do….Best Regards…Ken. 

[ken heppenerParticipant @kenheppener64998]

[CirclipParticipant @circlip]

Sure it IS Gunmetal and not Alumininininium Bronze??

 

   Regards  Ian.

[ken heppenerParticipant @kenheppener64998]

Hi Circlip…..As far as I know it’s gunmetal or perhaps maybe bronze…..not sure if there is Aluminium in there….Regards Ken.

[CirclipParticipant @circlip]

Is it magnetic??

 

   Regards  Ian.

[mgjParticipant @mgj]

You could also try sharpening the drill? Sharp drill, zero rake so it doesn’t grab, get the revs up, lots of coolant or proper RTD, clamp securely in a vice and press hard on the drill press.

 

Its more likely to be work hardening than anything else. Heat to red, hold it there for a few minutes, and then allow to air cool. should soften it.- or do I understand its actually a part of the boiler already?

 

If its already a part of the boiler, then go back to para 1 -can you get this thing into the drill press or milling machine? If not, then its a good sharp zero rake drill and press HARD.- don’t let it rub. Once it starts to cut, you will be well away. 

 

Tried a small pilot diameter?

 

[ken heppenerParticipant @kenheppener64998]

Hi Guys….No I could not get the boiler to the drill press, and yes it is already part of the boiler….I had thought of applying heat as you suggested but first I decided to buy a new drill and give it another go, and with heavy  pressure I managed to do the job…..Thank you both for your advice…..This is a great site for getting help…..Once again thank you….Regards Ken. 

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