Forbes & Company Limited

HSS-E/PM Machine Taps

Spiral Point Taps (SA)

Spiral Point Taps (SA)

Spiral Point Taps is also known as ‘gun nose’ or ‘bull nose’ or chipdriver. These taps are dimensionally the same as a hand tap, second lead, but have the cutting face ground back relative to the axis of the tap, for the lead portion.

This gives the flute a better cutting action, requiring less power, and pushes the cut material forward, allowing free flow of coolant along the flutes to the cutting edge.

The flutes are not ground as deeply as for hand taps, giving the tap greater strength. It can therefore be run at higher speeds. Spiral point taps are ideal for machine tapping of through holes, or blind holes where there is enough clearance beyond the threaded portion to accommodate the swarf.

Advantages

  • Thread Chamfer is of 4.5 threads & cutting load is distributed
  • Shallow flute depth, hence stronger tap
  • Chip clogging is eliminated as the tap pushes the chip forward and thus enhancing tool life.

Spiral Point Taps (SA)

Spiral Flute Taps (SB)

Spiral Flute Taps (SB)

SPIRAL FLUTE – These taps are used to produce a thread close to the bottom of a blind hole and therefore have a very short lead.

The right hand spiral cut of the flutes acts to force the swarf away from the cutting teeth to the rear of the flutes and out of the hole. They are better on materials which form long continuous stringy swarf, rather than chips.

They are also better to tap a thread in a hole where there is a break in the material, e.g. another hole, as the spiral fluting helps the tap to pick up on the other side. Spiral flute taps can have slow or fast helix angles.

Advantages

  • Can be used in both blind holes & also in through holes
  • Chips are pushed upwards due to spiral flute – Chip clogging avoided
  • Full thread depth can be achieved and this design prevents tap breakage

Spiral Flute Taps (SB)

Straight Flute Taps (SC)

Spiral Flute Taps (SC)

Straight flute taps dimensionally same as hand taps & with a lead chamfer of 1.1/2 threads. The flute & rake angle are designed as per application.

These Taps are recommended for tapping on grey cast iron, S G iron & steel. The chips produced are short or powder type with the help of special design provided in the tap

Advantages

  • Can be used in both blind holes & also in through holes
  • Chips are pushed upwards due to spiral flute – Chip clogging avoided
  • Full thread depth can be achieved and this design prevents tap breakage

Straight Flute Taps (SC)

Forming Taps (SD)

Forming Taps (SD)

Forming Taps otherwise known as ‘Roll’, ‘Fluteless’ or Polygon taps. Used for the chipless production of threads in ductile materials such as copper, aluminium, soft brass or steel. Threads produced by fluteless taps are formed by plastic deformation, they are not cut.

These taps do not have flute or cutting edges but have special roll forming lobes with circular land. They are operated at high speeds and are better at maintaining gauge qualification.

Because they produce no chips they are very suitable for blind hole application as well as through hole application.

Advantages

  • Can be used in both blind holes & also in through holes
  • Chips are pushed upwards due to spiral flute – Chip clogging avoided
  • Full thread depth can be achieved and this design prevents tap breakage

Forming Taps (SD)