uxcell HSS Lathe Tool Bit 4mm x 4mm x 200mm, Square Lathe Turning Tool Blanks, High Speed Steel Rectangular Fly Cutter Mill Blank, 5pcs

The 90 degree edges are quite sharp. For sparking off ferro rod works amazing. Not sure if careless will even cut my skin. The edge can be quickly taken off with belt sander.This HSS: amazing, can light paper and wood shavings due to tiny globs of ferro.It obviously removes more ferro rod with each strike, but with fewer strikes needed I think it will still allow a lot of starts. Compared to other tools I've tried...A file: very good, more easily start good tinder like jute, cotton ball, dry grass, fibre from dry bark.A knife spine made 90 degrees by filing or grinding: good, for good tinder, but doesn't seem to last.Won't ignite wood chips or paper, will ignite cotton balls, very dry grass, and fibres from dry bark.Hack saw blade: decent, takes strength but can light good tinder but takes several strikes.It doesn't take much to spark cotton or jute or very dry grass, but with this HSS takes less muscles and ignites less optimal tinder.

Nice length for cutting into 3 cutters for mini lathe. Holds an edge well

Easier to grind this smaller size, then put it in a holder, just like you'd do a carbide insert but HSS instead with your custom shape. Can braze to mild steel to put in a big aloris type holder on the lathe.Grinding half inch or larger HSS is for people willing to wait for their not yet conceived child to graduate from college. Ain't nobody got time for that.

I purchased these to make scraper for firesteel. Right out of the package not all 4 sides are equally sharp. A couple sides worked really well and through great Sparks, the other sides would only make small Sparks. I haven't tried yet but I believe a few strokes on my diamond knife sharpener and all the sides should work great. I feel it's a good value for what you get. I will be cutting them in half to make 10 strikers

These are great for making your own marking knife for woodworking. I epoxied some spare cutoff pieces from other projects and shaped it on the belt sander. I used the grinder to grind the bevels on each side so that I can mark from either direction for my joinery

The size of steel supplied was all over the place. Several pieces tapered from 2mm to 1mm, with a few waves to boot... Not a big deal as I bought it to grind shaped tools that are smaller than 1mm, however wasn't impressed with the lack of quality control.

I have made several tools and used it on sucker rod which is very tough steel. Works very well.

Work for making custom lathe chisels. Was able to shape on grinder with ease. Held a sharp edge against soft copper.