Need 16 to 32 microinch surface finish in 3.00 inch bore of alum die casting. Piston O-ring must seal 2500 psi on this surface.
First attempt to machine the required finish resulted in rougher finish (45-70). Part is machined on a Mazak machine. Hand polished bore and got required finish, but...
Have been told this is equal or better than 8620 for gears which have hardness of RC 58-62.
Can anyone comment on this? Chemicals are quite different. The 20CR material shows no Moly and the Ni and Cr are a lot lower than 8620.
Is there a simple way to estimate the difference in heat transfer for two cases.
1. Two steel surfaces in contact
2. An small air gap between the two steel surfaces
Would this be approx. the diff in thermal conductivity of air vs. steel?
Currently use a chrome plated formed bar which is 1/2" dia carbon steel with both ends bent down 90 degrees and flattened with holes in the turned down ends. The flattened end is approx. 1/4" thick. This is a tooled part and is chrome plated after forming.
Would like to try some type of SS bar...
Looking for a manifold mount valve (motor mounted) to operate at 2500 psi max and 15 gpm max using hydraulic fluid. Used for speed control. Cost needs to be less than $35.
Can be either bi-directional or uni-directional.
Have been using a 5/16" hex 4140 steel bar for 2 yrs and now can't locate. The bar is used as an input shaft and must be heat treated to Rc 20-26 and straightened within .020 in a 15" length.
Does anyone know where I can find this material?
An alternate of 12L14, heat treated to same hardness...
