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Tuesday, 10 December 2013

Hand Smythed Saws

Every week I get emails from far eastern circular saw manufacturers asking if we are interested in selling their saws. Every time the answer is the same - Thank you but we are very happy with our current supplier.

The reason for this is that there are only a handful of manufacturers left in the world who still smith and tension their blades by hand, and the product is inherently superior. Of those few companies, only one has a fully comprehensive range and the facility to manufacture special orders for us. They are based in Sheffield, so the industrial quality sawblades can periodically be sent back to the factory, re-sharpened on the machines that made them and have their tension and balance checked by one of the smiths that made them. These are not throwaway consumable items, they are proper tools, built to last.

When a circular saw blade is stationary there is no way that an untrained eye would be able to tell a hand smythed saw from any other, the difference is hidden within the metal of the sawplate.

If you imagine a circular saw in use, the perimiter is being heated by the friction of cutting the wood whilst the rest of the plate is being cooled by airflow. If you use just any old piece of steel, the opposing forces of expansion and contraction distort the saw plate and turn into the shape of a pringle. As soon as it cools down, it will return to flat.

With a hand smithed blade, the effects of the working loads are balanced by the tension in the sawplate. The only difference between working and stationary is a tiny increase in the diameter.

The process of making a handmade circular saw begins with the heat treatment, best hot rolled plate steel that has been laser cut to shape is annealed and then heated and quenched in a special press. This process makes the crystalline structure of the steel form correctly - so that the blade naturally wants to be flat. It is then tempered back to the correct hardness under the weight of a full sized millstone.

The heat treated saws make their first of three visits to the smithing shop, where a time served (5yrs+) saw smith tensions the blade using a selection of hammers and a special straightedge. Until recently the craft of sawsmithing was a closely guarded secret, the only people who ever saw the work being done were either qualified smiths or apprentices.

The processes of grinding the saw to thickness, brazing on the massive carbide tips and then shaping and sharpening them are all done by state of the art computer controlled machines to an accuracy of 1/100th of a mm.

Each saw goes back through the sawsmiths shop after brazing, so that the tension of the plate can be checked and adjusted if necessary. If you see any small hammer marks on the surface of a blade they will either have been made at this stage or the final check before the blades are passed as finished.

With a reasonable quality woodworking machine and the correct blade selected for the job, the stability and accuracy of a hand smythed industrial circular saw blade are unsurpassed.

If you would like to experience a proper hand smythed blade on your saw, they are available in sizes from 80mm to 915mm, with toothing patterns to suit all applications and centre holes bored or bushed to order.  

Workshop Heaven discount code AWWH25 will save you 25% on all industrial quality resharpenable saws, the same code can also be used for high quality, non-resharpenable, single life pro-trade blades.