Rob75

I sharpen other peoples chipper blades, TW150's are £10/pair hollow ground no matter how bad. They are done on the same fixture every time so the angle remains the same each time they are sharpened (which is exactly 42 degrees - manufacturers spec). Surrey/Sussex area You even get a reciept!

How much is 'ain't cheap'? -A steel version could become available....

That is the only draw back. And if you get a wider grinding wheel you need a lot more power to take the full width cut. More heat is also generated (even taking small cuts, so suds are important. To speed your process up try using a ceramic based wheel (either light blue or off white). More expensive than standard white wheel but much faster material removal and cooler to.

The radius is dressed in the 'thickness' of the grinding wheel. i.e there is a convex radius in the wheel. I manufactured a radius dresser for this purpose along with jigs to bolt popular bades to for exact blade angle and speed of set up. Blade angle on the little TW's is very important to machine life!

The TW blades are hollow ground (This causes the blade to plane rather than cut which is more efficient). I have a Similar set up on an automatic surface grinder although I generate the required radius in the wheel. This method gives a suberb edge and allows me to control the amount of material removed very acuratley giving extended blade life. (as opposed to aftermarket plough grinding with the radius being formed by the diameter of the wheel). Pair of TW's £10. discounted for quantities.

I have a small engineering Shop & have been sharpening Blades for a few guys for a little while as a 'side line'. I am thinking of making this a little more commercial to make use of the jigs & fixtures have made up for various common blades. Would any one let me know how much they are paying for a proffesional sharpen (not linished, angle or bench ground), type of blades, quantity turnaround etc. This will give an idea if it is financially possible. Thanks

I have seen blades bent (after a ratchet strap found its way through). Yes the front edge was damaged but no shattering. This shows a good level of hardening & tempering. Blades were Original TW. Most important thing (pattern or original) to remember is the keep them sharp as this reduces the loading on the blade & associated parts

Swedish i think, good steel but needs to be treated right.

The famous 'U' steel that the men up north use is 'X-rayed' for faults. Isn't It?! Incorrect tempering is a very likely cause here.

I have been sharpening blades for a few years now & have seen many made from various grades of tool steel. It is not just the steel that makes a good knife but the hardening & tempering process. I have had customers complain that some pattern knives dull quicker than OE's. Saturn use Bodycote (specialists) for the treatment processes but some blade manufacturers do it 'in house'. There is also the grinding/sharpening process which if not done correctly will over heat the blade and soften the steel. Another problem I have found with TW blades is an incorrect angle caused by the hollow ground Radius being off of the center of the cutting face. This can cause a drastically different angle at the cutting egde causing all of the associated problems including much faster dulling. I grind all blades on a precision grinder using very accurate tooling/fixtures, not only do i get a much better finish but blade angles & the hollow ground radius is allways spot on. I have seen many blades ground on aftermarket blade grinders which have a very different angle to the manufacturers spec.... :ohmy