Router Cutters Buying Guide...
With the blistering array of styles, profiles and shank sizes available, it is easy to forget that the router cutter is the most important part of any routing set up. The quality and design of the cutter will have an enormous impact on the resultant finish. With the development of computer aided design and manufacturing router cutters are now safer to use, better balanced and are more durable.
Anatomy of a Router Cutter
Unless they are bearing guided, router cutters have no moving parts, but it would be foolish to think of them as simple cutting tools. There are a number of very important design elements to a router cutter that determine how well it performs.
The cutter can be split up in to two distinct parts; the shank and the cutting head. The shank of the cutter is the only point of contact between the cutter and the router and this must be smooth, straight and of correct diameter for the router collet to clamp it correctly and securely. The entire router cutter is usually machined from a single piece of steel meaning the shank is integral to the cutter head.
Most router cutter heads have tungsten carbide tips brazed on to them although some cutters may be machined from high speed steel (HSS) or carbide and feature integral cutting edges. The cutting edges should run at a slight angle known as the shear angle. This allows the router cutter to cut in a similar fashion to a plane in that the wood is shaved, rather than chipped, away.
As well as sitting at an angle down the body of the cutter, the tips also sit at an angle to the axis of the cutter. This is referred to as the hook angle and assists with the chip clearance when cutting. The relief angle is, in effect, the bevel angle of the cutting tips. This angle is important as it prevents the cutter from scorching the wood during cutting.
Router cutters today have an anti kick back design. Kick back is caused when the cutting edge bites too deeply into the work piece and is unable to complete the cut. This results in the work being thrown by the cutter in the direction of its movement which is contrary to the direction of the feed. In certain circumstances, this can cause injury to the operator.
The anti kick back design features a shoulder set in front of the cutting edge that limits the depth of cut. The deeper a cutter attempts to cut, the higher the risk of kick back. ©
Types of Router Cutters
Straight cutters are possibly the most versatile type of cutter. As well as being used for putting a straight, square edge on work pieces, these cutters can also be used for cutting rebates, grooves and dadoes. Used in conjunction with a guide bush, straight cutters are often the cutter of choice when following a template. Straight cutters can be used in a router table for jointing work also. ©View our Range of Straight Router Cutters
Joinery router cutters are those cutters that shape all or part of a joint. These include rail and stile cutters for panelled doors, tongue and groove cutters, glue joint cutters and mitre joint cutters. Some types of joint require two cutters that cut opposite profiles such as the rail and stile and the tongue and groove. Other cutters are capable of cutting both sides of the joint and require only that the two pieces being joined are presented to the cutter in different positions. Joinery router cutters are usually designed for use in a router table only. ©View our Range of Joinery Router Cutters
Grooving cutters produce a V-shaped channel and can be used for lettering, etching designs and giving a jointed tongue and groove look to a solid panel. V-groove cutters can also be used to create bird's mouth joints and putting a chamfered edge on square stock. ©View our Range of Grooving Router Cutters
Lettering & Template Following
Lettering and template following cutters are designed to give a smooth finish with minimal tear out regardless of the shape of the cut. Some of these cutters have bearing guides attached whereas others require the use of a guide bush. These cutters give a decorative etched, carved or engraved look depending on the profile. Smaller diameter cutters are ideal for freehand work, larger diameters must be used in a router table. ©View our Range of Lettering & Template Following Router Cutters
Plunge profile cutters can be used for adding detail and designs such as creating a panelled design on a plain door. Unlike with bearing guided cutters, the plunge capability allows the cutter to begin the cut away from the edge of the board. This is particularly useful when you need to add a design to the middle of the board. Plunge profile cutters can be used with a guide bush for edge and template work, if required. ©View our Range of Plunge Profile Router Cutters
Edge profile cutters are used for cutting profiles around the edges and on the faces of work. This type of cutter comes in all shapes and sizes with some featuring an attached bearing guide and others requiring the use of a guide bush. The small diameter cutters may be used freehand in a router, the large cutters must be used in a router table. The large cutters are used for creating architectural mouldings such as skirting boards, architraves, coving, dado and picture rails. ©View our Range of Edge Profile Router Cutters
A rebating cutter is used to cut a rabbet which is a long recess on the edge of a board. Used for jointing and other projects such as creating inset doors and drawers, rebating cutters come in many different sizes. These cutters feature bearing guides and the depth of the rebate produced is determined by the diameter of the bearing in relation to the diameter of the cutter; the smaller the difference in diameters, the smaller the rebate will be. Some rebate cutters are supplied as one cutter with a number of differently diametered bearings giving the option of mulitple sizes of rebates from one cutter. ©View our Range of Rebating Router Cutters
Slotting cutters are large diameter, thin cutters that produce slots and grooves. Used for cutting grooves, slots and rebates, biscuit jointing and also for tongue and groove joinery, slot cutters are usually a cutting head with a guide bearing mounted on an arbor. These cutters may be used freehand in a router although it is recommended that the larger diameter cutters are for router table use only. ©View our Range of Slotting Router Cutters
Some of the largest router cutters available, raised panel door cutters are used for putting the wide sweeping profiles on the panels in the centres of the doors. Due to the large diameter of the cutter, these are for use only in a router table. There are variations of this cutter available; vertical raised panel door cutters are ideal for use with a lower powered router as these do not have the physical mass or large diameter of the standard bits. The raised panel door cutters with undercutting are used for thicker panels and these produce a 6mm lip around the panel that fits in to the groove in the frame of the panel door. ©View our Range of Raised Panel Router Cutters
Used for trimming laminate and veneer facings and edgings, trimming cutters are bearing guided to give a perfectly flush finish. Designed to cut smoothly without splintering, trimming cutters are available to give either a square or chamfered edge. Generally mounted on 1/4" shanks, trimming cutters feature bearing guides and are designed for free hand use but may be used in a router table if required. ©View our Range of Trimming Router Cutters
Features to Consider When Buying a Router Cutter
1. Shank Size
For many router users, the choice of shank size is not an option. However, if your router comes with more than one size of collet, it is worth considering which size shank to opt for. The shank diameter on a router cutter does have an influence on how the cutter performs. The larger the shank diameter, the less likely the router bit is to vibrate during cutting. Excessive vibration of the cutter will give a poor cut. This does not mean that you will always get a poor cut from a 1/4" shank cutter though. Larger diameter cutting heads as well as longer length cutting heads can also suffer from vibration. When you have the option, select a cutter with the largest shank size your router will accept. ©
2. Type of Material Being Cut
The type of material you are intending to cut should influence your choice of cutter. Tungsten carbide tips are excellent for cutting softwoods, hardwoods, plywoods and even some plastics. The tips on these cutters remain sharper much longer than solid high speed steel cutters which become dull very quickly. For exceptionally abrasive materials such as particle board and MDF, solid carbide cutters are preferable as they are even harder than tungsten carbide tipped cutters and take even longer to dull. When selecting a cutter consider what you will be cutting and how much cutting you will be doing. ©
3. Freehand or Table Mounted Routing?
The diameter of a router cutter gives a good indication of whether it can be used freehand or requires the use of a router table. Router cutters with smaller shank diameters such as 1/4" and 8mm have correspondingly small cutter heads and are ideal for use freehand, as are 1/2" shanked cutters with small diameter cutting heads. 1/2" shanked cutters with larger diameter cutting heads like those used for face profiling or joint creation should only be used in a router table. ©
4. Bearing Guided
Bearing guided cutters allow the cutting of a straight or curved edge without the need for a router fence. The bearing references the face of the work allowing the cutter to follow the shape of the edge precisely. Bearing guides are also useful when using a template as the bearing will follow the template while the cutter shapes the work. Bearing guides eliminate the need for guide bushes and specialist base plates. ©
The flute is the part of the router cutter that makes the cut. The number of flutes a router cutter has affects both the speed and the cut. A single flute cutter cuts very quickly, but leaves a rougher finish than a cutter with two flutes would. The higher the number of flutes, the slower the router cutter cuts but the smoother the finish will be. ©
Tips From the Experts
1. Never attempt to cut a full profile in one pass, this will result in a poor finish. By taking a number of passes to form the profile, removing a small amount of stock each time, the resultant finish will be much smoother and far more professional looking. ©
2. When making freehand straight cuts, use either a bearing guided cutter or a router fence to ensure the cut is perfectly straight. ©
3. Featherboards will help keep the work piece flat to the table, flat to the fence and, more importantly stop the workpiece from flying backwards as a result of kickback. ©
Tornado router cutters are produced using the very latest manufacturing technology. Computer controlled design and production ensures that every cutter is geometrically correct and perfectly balanced to give the best possible performance. Each cutter incorporates an anti-kickback design that is certified to the strict German DIN 847-1 standard. These best selling cutters are also quality approved by HBG in Germany.View our Range of Tornado Router Cutters
Sharpening & Maintenance
Dull router cutters will tear and even scorch the wood during cutting. If this starts to happen then the cutter needs sharpening. ©
Router cutters may be sharpened by hand using a small diamond stone or file. ©
Care should be taken not to change the shape of the cutting edge as this will effect the geometry and balance of the cutter and will result in a poor cut. ©
Router cutters are prone to rust. When not in use, a coating of light tool oil will protect them or store them individually in corrosion inhibiting bags. ©
Ensure the shank of the cutter is clean and smooth at all times. ©
Any rust or corrosion can be removed from the cutter using 0000 wire wool. ©
Remove any debris and resin from the cutter after use. Some specialised cleaning products offer protection against resin build up and are ideal if you rout resinous woods such as pine. ©
Replace bearings as soon as they stop rotating freely and start dragging. ©