Material Comparable to 1018 for knife blade

[HAVENOIDEA]

I would like suggestions as to what material I could use to make new knife blade bars. Currently, one of the bars is partially hollow and the other is solid. I need both to be hollow, with minimum wall thickness- the lightest we can get it and still have it as strong, the better. Was thinking of 4140, but not sure of the necessary wall thickness. the bars are approx. 44 1/2 inches long by 3.44 inches in diameter and 40 1/2 inches long by 3.44 inches in diameter. Any help is appreciated, thanks in advance.

 

[CoryPad]

Does the bar have a sharp edge, or just support a blade?

If the bar has to do the cutting, then 1018 won't stay sharp for long (low carbon concentration, low hardness, high wear rate).

4140 in the quenched and tempered condition could be used.

Tool steels are more typical.

Wall thickness would depend on forces, which we cannot estimate without additional information like workpiece size, thickness, and strength.

The more information you provide, the better tips you will get.

Regards,

Cory

Please see FAQ731-376 for tips on how to make the best use of Eng-Tips Fora.

 

[HAVENOIDEA]

it just supports a blade in the middle, and lets say the bar needs to hold up to a 100 lb force. sorry i forgot to add that in there. thanks.

 

[EdStainless]

Then strength isn't really an issue, and stiffness will be a matter of the OD. You can get heavy walled tubing in alloys like 1026 or St52.3 that would work as a holder.
What wall can you get by with?

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[HAVENOIDEA]

what im looking for ideally is the smallest wall thickness possible in order to achieve around the same strength that you get with solid 1018 CRS. Thanks.

 

[NickE]

Strength or Stiffness? (They are different things)

As has been pointed out in many threads, the stiffness of 1018 is going to be roughly the same as the same geometry of 4140.....

 

[MikeHalloran]

Uh, Have, you need to get an actual engineer onsite for a while to help you with this problem. The rent is pretty modest these days.



Mike Halloran
Pembroke Pines, FL, USA