Saws
23 March, 2013 Leave a comment
Saws – 70-90mm piercing or jewellers/jewelers saw (ess.), and associated blades, maybe #1 and 1/0, certainly 2/0, and for thinner material or fine detail 4/0 or finer. Hacksaw and coping saw. For jewellers saw blades, the larger the number, the finer the blade. 2/0 is the standard for cutting thicker pieces of metal, 4/0 is for small and fine detail. Use what is comfortable.
Otto Frei saw blade and saw frame page.
The jewellers saw is an essential tool for the manufacturer and is the most versatile of all cutting equipment. It will cut straight lines, angles, go around tight curves and can even be used as a file (for those places that are a bit awkward to get a file into). A saw with the blade inserted correctly also wants to cut. You don’t have to apply any pressure at all and it will go where you point it. Thick and thin material, hard or soft, and it doesn’t distort or damage the metal, other than the vacant line it leaves behind as you cut through.
This image (Fig.1) shows a collection of standard jewellers saw frames, often called piercing saws. There are basically two types of saw frame, rigid (A and B) and adjustable (C and D). Model A is a “Swiss Rigid” (also available as adjustable), model B an “English Rigid” and model C is a “German Adjustable”. There are many variations of both rigid and adjustable frames, some of them being ridiculously expensive, others needlessly fancy. The centre two frames can be purchased for less than $10 each and they are the ones I would buy, they are the ones I use. If you are going to purchase just one, get an adjustable frame with an 85-95mm throat. It is the most versatile, they are cheap and spare knobs are readily available. They will last a lifetime. Frame B is over 25 years old while frame D is over 40. Both are used nearly every day.
A 90mm throat will enable you to carry out ordinary jewellery manufacturing and repair work without the need for special cutting tools. A plain ring blank, for example, will never likely be greater than 90mm long. That 90mm throat allows you to cut a length of material for any ring up to that size from a sheet of metal. Frame C has a throat of 70mm, a little short to cover all the possible ring sizes but it is a great size when you do intricate work and your eyes need to be a little closer to what you are cutting. Those wearing glasses or magnifying units (a nose can get in the way too) will find the narrower frame less trouble.
These next two frames (Fig.2) are designed for cutting particularly long strips or lines and the frame on the right will allow you to cut 300mm into a sheet of material. These frames might be used to cut material for bangles or neck pieces. Those interested in silver-smithing would use one to cut discs for a bowl, sections for boxes or blanks for cutlery. Most metal suppliers will provide sheet and strips cut to order, so these frames are not an essential part of the jewellers toolkit. But if you prepare your own material, they are handy to have. The adjustable versions are available up to a depth of 200mm. Again, they are inexpensive in this style.
A side benefit of the adjustable frame is the ability to recycle broken blades. Blade packs come in twelve lots of twelve – called a gross. They can be fragile and to some, expensive. I was employed in a workshop that made trophies and on one occasion, the master allowed two apprentices to cut the pieces for a particular trophy. They broke over 1100 blades making it. With experience, you will become flippant with blades. I sometimes go for a week or two without breaking one; other times I break them as I pull them out of their slot. In humid environments, because of rusting, they break as quick as you look at them. Either way, when they are broken they are binned. The adjustable frame allows you to shorten it to accommodate a broken blade if you wish, a great way to save money.
Now, the metalworkers saws. All these saws are readily sourced from a hardware store. Model F is a coping saw, used more for woodwork than metalwork but blades are made for use with metal. The blade is rotatable and as such, the back of the frame may be perpendicular to the cutting line rather than behind and following it. Any angle in between is possible as well. The coping saw will also allow you to follow shallow curves. While similar in appearance to the jewellers saws above, it is not a replacement and lacks the ability to follow tight curves. The hacksaw, model G, lives up to its name. Designed for grunt work as it were. For thick rod, bars, sheet, if you have to go at it hard, it’s the one to go for.
All of these saws are used in my workshop, some everyday, others rarely so. Over the years, you will probably find that all will have come into your possession. $10 is all you need to get started though. That will get you a decent adjustable frame and a pack of 12 blades. You might break them all before you have finished your first piece, but even a good jeweller has days like that.