Which grade of hardox for workbench surface?

[drummerdimitri]

I'd like to fabricate a workbench for general metal fab shop work such as grinding, cutting, hammering, welding, clamping and fixturing etc. and thought of installing a hardox plate on top of the base instead of mild steel for longer service life and less wear/dings over the years.

Problem is, I'm not sure which grade of Hardox to go for. There is the 400, 450 and 500 locally available and their prices are 5$, 5.5$ and 6$ per kg respectively.

For a 2mx1m plate with a thickness of 12 mm, that comes out to be quite a hefty investment.

Would the 400 be enough or should I spend a little extra for the higher grade steels?

Also, I will be using my mag drill on the surface of the plate and since the manual says that I would need a steel surface of 12mm thick or more for full magnetic holding force, would it be the same for Hardox or does it have different magnetic properties vs mild steel?

 

[jack stand]

Personally I'd spend my money on thickness and weight over abrasion resistance and hardness. As for a mag drill, I find that 3-4" of free clamping space around the edges of the top is important, I'll drill over the edge (if possible) to avoid having to space up the material to avoid drilling into the actual top.

 

[rockbaron1]

For a work bench top I don’t think it matters to be honest. I have a 3/16” thick skid plate for my rock crawler made from ar-450. It’s roughly 4’x4’ sheet with no added structure and and can support the weight of my 5,000lb truck on a point load in the middle without deforming. Also good scratch resistance but forget about drilling holes through it.

 

[Firebrick43]

I'd like to fabricate a workbench for general metal fab shop work such as grinding, cutting, hammering, welding, clamping and fixturing etc. and thought of installing a hardox plate on top of the base instead of mild steel for longer service life and less wear/dings over the years.

Problem is, I'm not sure which grade of Hardox to go for. There is the 400, 450 and 500 locally available and their prices are 5$, 5.5$ and 6$ per kg respectively.

For a 2mx1m plate with a thickness of 12 mm, that comes out to be quite a hefty investment.

Would the 400 be enough or should I spend a little extra for the higher grade steels?

Also, I will be using my mag drill on the surface of the plate and since the manual says that I would need a steel surface of 12mm thick or more for full magnetic holding force, would it be the same for Hardox or does it have different magnetic properties vs mild steel?

So you’re a sadist?

Drilling ar400 takes slow rpm’s down in the 100 range. It also takes carbide and lots of down pressure as to not harden due to rubbing.

It’s terrible on a large stiff milling machine or massive radial drill press and will absolutely **** donkey balls with a mag drill.

 

[drummerdimitri]

Personally I'd spend my money on thickness and weight over abrasion resistance and hardness. As for a mag drill, I find that 3-4" of free clamping space around the edges of the top is important, I'll drill over the edge (if possible) to avoid having to space up the material to avoid drilling into the actual top.

I took your advice and bought a 20 mm thick plate of mild steel instead.

It was around 3 times cheaper and will surely last decades. Flatness doesn't really matter after all since I already have a nice Siegmund welding table so this will do nicely.

 

[Walkers]

I took your advice and bought a 20 mm thick plate of mild steel instead.

It was around 3 times cheaper and will surely last decades. Flatness doesn't really matter after all since I already have a nice Siegmund welding table so this will do nicely.

Nice! Good choice, you will be happy with that.

 

[drummerdimitri]

Took two days of work but it was worth it in the end

 

[Fixr]

That looks like it should be quite adequate.

 

[Jswain]

Looks great. Good choice on the thicker mild steel plate