83.6mm Stroke 4340 Billet Cranks for Nissan CA18

Technical Features：

• Materials:40CrNiMoA, Heating treatment:HRC34-38

• Crankshaft will get thermal refining after normalizing,HRC34-38.The difference will be within 4HRC on same one cranks

• No over burning,carbon-free surface layer is within 0.3mm 

• Folding,oilet,cracks, oxidation and other things is not permitted for Cranks macrostructure.

• Balance weight value need keep 0-20g.cm on counterweight of big end and small end

• Peening treatment will be done after balance weight 

• Nitrogen treatment will be done after precision grind,compound layer depth is 0.008mm after polishing.diffusion layer is over 0.3mm,hardness on surface is not less than 500HV.

• No damage,scallops and other visible disadvantage on surface.

• Crankshaft will be cleaned up to make sure there is no filings in oil hole.

• magnetic flaw detecting will be done according to standard JB/76729-93

• Other size tolerance :standdars GB1804-79 IT14,No marked place roughness:Ra6.3