What materials are really hard on a knife's edge?

[Vivi]

I now use scissors or an iSlice (ceramic tip cutter) for clamshell packs as too great a risk of slippage injury from a knife

Ray and sharkskin seem to blunt most knives real quick - they really need blades with 62+ RC

Spyderco Spin or Cricket also work well for this task

 

[Fort Henry Custom Knives]

From my experience I will say - in this order;
Old Carpet
Recycled Corrugated Boxes
Leather
Cuttnig on a Glass Cutting Board

 

[MValborg]

fiber-glass

 

[coop1957]

I've used my Benchmade VEX to dig weeds out of the ground. I know wrong tool for the job. Dirt really dully a knife up fast. I should have known that, dirt is the fastest way to dull a chain saw blade.

 

[mnyshrpknvs]

High density fiberpanels. I run a bedding store and the fiberpanels will dull the edge very quickly. They are pcs of yarn and thread compressed together under extreme weight and pressure to create a firm top on a mattress.

 

[Paul B12]

If not used for ALL of the above what use or good is a knife?????

I guess I'm just plain hard on all my knives because I cut just about anything with mine, including my newest toy HK14905 Benchmade.

JMHO..............

Paul B12

 

[THG]

If not used for ALL of the above what use or good is a knife?????

Agreed.