In article , Mark Rand writes
Doh - I forgot that carbon fibre is only stiffer weight-for-weight.
Not my boring bars - mine are mild steel with tungsten carbide tips, and flex like anything - teach me to cheapskate with Chinese stuff !
A set of Arrand bars is on my Christmas list - anyone here got any experience of them ?
I've been trying to stop her doing that for years - makes a terrible mess of her false teeth...
All grades of steel have about the same Young's Modulus. Composition and heat treatment will affect the tensile strength and hardness but the Young's Modulus stays resolutely the same. Mild steel is therefore as good a material for the shank of a boring bar as the best high alloy heat treated steel. I know, it bugs me too and doesn't seem totally logical but it appears to be the case.
-- Dave Baker
In article , Dave Baker writes
But Tungsten would be better ?
Of course. It has a higher Young's Modulus.
-- Dave Baker
Yep - you are right. Composition of the alloy has only a very minor effect on the Youngs modulus, and the state of hardness none at all.
The state of hardness/temper affects only the point at which you reach elastic limit & what happens when you do - deformation vs the material fracturing.
Regards, Tony
This is not an insignificant consideration. I have a home made 1/2" 10tpi ACME tap that has an interesting corkscrew section in the bit that didn't get hot enough when I was hardening it.
Mark Rand RTFM
These particular tools were not only tungsten, they were about 3" tall by 1/4" wide to hold a 3/8" diameter round ceramic bit. Seriously stiff. IIRC they are used to cut the slots between blade disks on aviation gas turbine rotors.
Mark Rand RTFM
Shhhh!
Keep schtum and patent it. No one will ever know.
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