Punches

Punching tools are made in various weights and patterns and are designed to do any kind of piercing or penetrating work, varying from punching location marks for nails or calipers to making holes in sheet metal. Most punches are held in one hand (the shaft is usually knurled to prevent it slipping) and driven, but there are automatic punches and one that can be used by hand only. The anvil or striking part of the standard punch is shaped to be driven either with a mallet (for woodwork) or a hammer (for metalwork). Anvils that are damaged must be reground to their original shape for efficient usage. When using the heavier punches, back up the work with lead cake or blocks of end grain wood. Lever and revolving punches, which are mostly used for leatherwork, incorporate their own back-up.

Nail Set

OTHER NAME: Nail punch

SIZE: Length: 4in.: Point diameter: 1/32 to 3/16 in.

MATERIAL: Steel

USE: To drive the heads of nails below the surface of wood

Holding the nail set

The set is held perpendicular to the wood between fingers and thumb of one hand,

Catapunch

SIZE: 41/8 in.

MATERIAL: Steel

USE: To mark centres on metal or wood without the use of a hammer

The catapunch can be used to mark centres on metal or screw positions on wood. It consists of a pointed head mounted on a coiled spring shaft.

Using the catapunch

Hold the pointed end of the tool against the work with one hand. Extend and release the spring to mark the surface.

Dot punch

OTHER NAME: Prick Punch

SIZE: Length: 4 to 5in.; Point diameter:3/32 in.

MATERIAL: Steel

USE: To clarify marked out metal work, identify intersections, and mark hole centres prior to centre punching

The prick punch is similar to the nail set, but it has a sharp conical point with an included angle of 30. It is used for the final marking out of the cutting lines on metal work. It does this by accentuating the lines with a series of small punched indentations. It can also accurately mark out a hole centre before the mark is enlarged with a centre punch prior to drilling. Moreover, the punch mark made by a prick punch is ideal for setting the point of a pair of dividers.

Using the punch

Hold the punch as you would a nail set and position the point on the mark. Lean the punch away from you to see the point clearly. When accurately centreed stand the tool upright and strike the anvil end lightly with a hammer.

Correcting the centre point

If your first attempt at making the mark does not exactly correspond with the intersection, angle the punch toward the centre and strike again: this will move the punch mark to the exact centre. Even up the punch mark by holding the tool perpendicular and striking it again.

Centre Punch

SIZE: Length: 4 to 7in.; Point diameter: 1/8 to 1/4 in.

MATERIAL: Steel

USE: To mark hole centres or enlarge the prick punch marks to guide the point of a drill

The centre punch is exactly the same as a prick punch except that it has a blunter point, ground to an included angle of between 60 and 90 . It may have a round or square sectioned anvil.

Use the centre punch in the same way as the prick punch.

Automatic Centre Punch

SIZE: Length: 4-1/2 to 6 in.; Pressure: 5 to 50lb

MATERIAL: Various

USE: To mark centres on metal without using a hammer

The automatic centre punch does exactly the same job as the normal centre punch, but works in a different way. The point is positioned on the required intersection and the tool pushed down. This automatically releases a striking block which punches the point into the metal. On some models the force can be adjusted. The points are interchangeable.

Starting Punch

OTHER NAMES: Drift punch, drive punch, motor and reaper punch

SIZE: Length: 6 to 8in.; Point diameter: 5/32 to 1/4 in.

MATERIAL: Steel

USE: To start the removal of a pin from an assembly

The starting punch has a strong tapered point capable of resisting the force applied to it in order to free a pin from its housing. The end of the point should be j ust smaller than the diameter of the pin. Set the point on the pin and strike the "anvil" with the hammer. Drive the freed pin from its housing with a pin punch.

Sheet Metal Punch

OTHER NAMES: Stop punch, screw nail punch, corrugated iron punch

SIZE: Length: 7in.; Diameter: to suit fastening

MATERIAL: Steel

USE: To punch holes through sheet metal to take fastenings

These punches produce the appropriate holes required by various fastenings such as self-tapping screws and screw nails. They are quicker to use than a drill. Some have a straight cylindrical point matched in size to the fastening arid a shoulder, which stops against the metal. Other punches taper to a sharp point and must be struck to produce the hole.

Making holes in sheet metal

You can use a drill to make the holes (left) but a sheet metal punch produces a stronger fixing which gives the screw thread more purchase.

Pin Punch

SIZE: Length; 4 to 6in.; Point diameter: 1/16 to 3/8 in.

MATERIAL: Steel

USE: To drive out a pin from an assembly

The pin punch has a straight cylindrical shaft with a square end. Match the punch as near as possible to the size of the pin to be removed. If the pin is tapered, check which is the smallest end and choose a pin punch to match it. To remove a pin, centre the punch on it and tap the end with a hammer. Do not apply too much force until the pin has begun to move. If the pin has frozen in the housing do not attempt to free it with a pin punch, but go back to a starting punch.

Lining Up Bar

OTHER NAME: Aligning punch

SIZE: Length: 12in.; Point diameter: 1/4 in.

MATERIAL: Steel

USE: To line up holes to take a fastening

The lining up bar is not a punch in the normal sense. Its long tapered point is inserted in the holes which need to be lined up to take a pin or bolt.

Tinmen's Hollow Punch

SIZE: Hole diameter: 3/8 to 1in.

MATERIAL: Steel

USE: To punch holes through thin sheet metal

The hollow punch has a solid metal shank terminating in a sharpened, hollowed end. Back up the work, mark the centre of the hole with a prick punch and use dividers to scribe the diameter to be punched. Centre the hollow punch on this mark and lightly tap the end with a heavy hammer. Adjust the position of the tool if necessary and strike it again with a heavier blow to cut through the metal. Correct any distortion with a hammer rather than a mallet.

Using the hollow punch

Strike the end with a heavy hammer. Thicker materials may need more than one blow.

Use a thick material such as lead cake or an end grain wood block to prevent distortion.

Backing up the work

Use a thick materia1 such as lead cake or an end grain wood block to prevent distortion

Solid Punch

SIZE: Length: 6 to 6-3/4in.; Point diameter: 1/16 to 1/4in.

MATERIAL: Steel

USE: To punch small holes in thin gauge sheet metal

A solid punch makes it easy to punch a hole in thin sheet meral up to ^in. diameter. You could use a drill, but this is more difficult: the end of the drill has to be ground to a shallow point to avoid heavy burring on the underside of the metal and to reduce the risk of snatching.

The work must be backed up by material thick enough to prevent too much distortion of the metal sheet when cutting. A professional metal workshop might use a lead cake, but an amateur would be better advised to use the end grain of a block of lumber.

Using the punch

Mark the centre of the hole with a prick punch, place the solid punch over the mark and tap it lightly with a heavy hammer. Check that the resulting mark is centreed over the prick punch mark, replace the punch and strike a heavy blow to cut through the metal. There will be a slight conical depression around the hole, which could be useful if a countersunk head screw is to be inserted. Otherwise, flatten the depression with a mallet.

Lever Punch

OTHER NAME: Punch plier

SIZE: Hole diameter: For metal: 3/32 to 9/32 in.; For leather: 5/64 to 3/16 in.

MATERIAL: Various

USE: To punch small round holes in sheet metal or leather

Lever punches incorporate an interchangeable punch and a matching die or "anvil". The die backs up the material, prevents distortion and leaves a clean hole. This type of punch can only be used near the edge of the material because of the depth of the throat. The tool is operated by squeezing the handles together.

Turn the sheet over and flatten the bulge with a mallet or hammer, using a block of wood to protect the work.

Crew Punch

OTHER NAME: Oblong punch

SIZE: Slot length: 1/4 to 1-1/8 in.

MATERIAL: Steel

USE: To cut buckle slots in belts or straps

Crew punches are hollow punches which cut slots with rounded ends instead of round holes. The slots are made to accommodate buckle pins on belts or straps.

Wad Punch

OTHER NAME: Arch punch

SIZE: Diameter: i to 3in.

MATERIAL: Steel

USE: To punch large round holes in leather

The smaller wad punches can be used to cut holes in belts or straps but the larger ones may be used to cut disks of leather from the hide ss well as larger holes. The name may derive from the fact that they were used to cut the "wad" or soft washer which is packed into guns along with the charge to make a gas-tight seal. Even today they are often included in the tool kit supplied for muzzle-loading sporting guns.

Saddler's Hollow Punch

OTHER NAME: Belt punch

SIZE: Hole diameter: up to 1in. (numbers 0 to 22)

MATERIAL: Steel

USE: To punch round holes in leather

The saddler's punch is used to punch holes in belts or straps. The punches are designated by numbers which refer to the diameter of the hole produced. Number 6 for example will punch a hole of 3/16 in. while number 22 will be 1in.

Where a strap is fitted with a buckle the slot allows the pin to move freely for easy adjustment.

Using the punch

Position the punch on the work and strike the end with a mallet to cut the required hole.

Revolving Head Punch

OTHER NAME: Six way punch pliers

SIZE: Length: 8 and 9in.; Hole diameter: 5/64 to 3/16in.

MATERIAL: Various

USE: To punch small round holes in leather or other soft materials

The revolving head punch pliers incorporate the punches used in the standard lever punch. One of six sizes can be selected by revolving the head to line up with a soft metal anvil on the lower jaw.

Wheel Pricker

OTHER NAME: Stitch marking wheel

SIZE: Measured in points per in.

MATERIAL: Wheel: stainless sieel; Handle: hardwood

USE: To mark out a row of stitching

An evenly spaced row of stitching, although not essential for strength, makes leather work more attractive. Run the wheel pricker along a predetermined line to insure this even spacing. Then use an awl to pierce the marked holes in the leather.

Pricking Iron

SIZE: Measured in teeth per in.

MATERIAL: Steel

USE: To mark out a row of stitching

The evenly spaced teeth of the pricking iron can mark out a row of stitch holes which are then pierced by an awl. Position the iron along the intended line of stitching and strike the end with a mallet. Continue the row by moving the iron and positioning the first two teeth in the last two marks to insure alignment and repeated even spacing. Keep striking and repositioning the iron until the row is complete. Thin leather can be pierced using the pricking iron alone.

Using the iron

Place the first two teeth into the last two marks for accurate alignment. Strike with a mallet,

Awls

OTHER NAME: Bradawls

SIZE: Blade length: 1-1/2 to 3-1/2in.

MATERIAL: Blade: tempered steel; Handle: beech, boxwood, plastic

USE: To make starting holes for screws and nails in lumber and to pierce holes in leather

Awls are made with blades of various section: round, square and diamond shaped. When pressure is applied all produce holes by pushing the fibers of the materia! apart. This works well with leather, but wood is apt to split along the grain unless a screwdriver type tip is used to make a starter hole. These tips are designed to overcome splitting by cutting the grain before the hole is made. When necessary repair awl tips with a smooth file and finish on an oilstone.

Bayonet awl blades

These are used for leatherwork and are made without handles. They terminate in a tang which fits into a holder.

Piercing leather

Keep the awl handy to cut thread holes as necessary while working along the length of the leather.

 

Piercing wood

Position the cutting edge across the grain and apply pressure, turning the tool to the right and left with a twist action only.