metal hardness for parts

[TONYT]

i'm lookin at some rods and cranks for a stroker build and was wondering what is the least to the strongest metal strength ratings IE

4340-----5150

could someone list them or point me 2 a site that has em in order of hardness


thanx

[outlaw85]

As far as rods and cranks go 5150 is the low end of the spectrum and 4340 is the higher side as far as fatigue strength. With today's sbf rotating assembly's the price difference isn't a whole lot to go ahead and get the 4340 stuff but my rule of thumb would be if it's going in a production 302 block (550hp. or less) get the cast cheaper materials due to the block being the weak link anyways. Whats your plan to build? Below is some charts for 4340 and 5150 we use at work. Just my 2 cents!!




Mechanical Properties - 5150 Steel
Properties Conditions
T (°C) Treatment
Density (×1000 kg/m3) 7.7-8.03 25
Poisson's Ratio 0.27-0.30 25
Elastic Modulus (GPa) 190-210 25
Tensile Strength (Mpa) 675.7 25 annealed at 825°C more
Yield Strength (Mpa) 357.1
Elongation (%) 22.0
Reduction in Area (%) 43.7
Hardness (HB) 197 25 annealed at 825°C more
Impact Strength (J)
(Izod) 25.1 25 annealed at 825°C


Mechanical Properties - 4340 Steel
Properties Conditions
T (°C) Treatment
Density (×1000 kg/m3) 7.7-8.03 25
Poisson's Ratio 0.27-0.30 25
Elastic Modulus (GPa) 190-210 25
Tensile Strength (Mpa) 744.6 25 annealed at 810°C more
Yield Strength (Mpa) 472.3
Elongation (%) 22.0
Reduction in Area (%) 49.9
Hardness (HB) 217 25 annealed at 810°C more
Impact Strength (J)
(Izod) 51.1 25 annealed at 810°C

[TONYT]

looking to put together a 351 with a fms 351w crank and spacer kit,and the crank is marked ams 6514, was wondering how that stacked up against 4340 and the like

[Timido]

I think what ever crank and rods you use the block is still the weakest legth. If you are running NA I wouldnt worry alot about having the best crank and rods you can buy. I was told to keep my RPMs reasonable I shift at 6500. I was told to keep the timing reasonable I run 27-28 degrees timing. That is would last a long time and it has. If you are running a spacer kit is that a 2.75" crank?