In die tapping

For most stamped parts with a tapped hole or holes, IN-DIE TAPPING has become the only competitive alternative to secondary tapping. Secondary tapping of stamped parts has always been far more costly than the stamping operation.

Hutchison tapping heads can cover a wide tapping range from #2-56 to 1-11/4” – 12 or metric equivalent, for multi-spindle hole patterns as well as single spindle units.

In the past year, Hutchison have consulted on 1,289 separate Drilling, Tapping and Machining projects. These projects resulted in customer savings ranging from $26 to $236,000 per project.

Single-Spindle Tapping Units

Press speed up to 250 strokes per minute
Compact design and simple installation
High torque driver extends service life
Quick change twist lock lead screw assembly
Change taps in seconds while in the press
Uses standard cut or roll form taps
Lead screw tapping assures quality threads
Through-Tool Coolant Capabilities
Misfeed protection prevents tap breakage
Change tap size and pitch in only minutes
Solid steel construction, made in the USA
Change from die to die in minutes
Capacity 2-56 to 1-1/4"-12 (or metric equivalent)

Multi-Spindle Tapping Units

Multiple spindle tapping units have distinct advantages over individual in-die tapping units. Parts with multiple tapped holes can often be tapped in a single station which saves die space and tooling costs.

Twist lock lead screw assembly - any combination of pitch and tap diameters can be combined in a single multiple unit.
High torque driver can tap as many as eight 5/16"- 18 holes in a single tapped part.
Custom in-die tapping units built to customers specifications - options include top down, bottom up, or rapid advance multiple spindle in-die tapping units to fit requirements while keeping costs to a minimum.

Strip-Following Tapping Units

A strip-following tapping unit can begin to thread the part as soon as the material feeds into position, allowing for a larger tapping window during the press cycle. A larger tapping window translates into lower gear ratios, and the lower the gear ratio the faster the press can run and still maintain the proper rpm on the tap. In some cases, when tapping in higher-stroke presses, production rates can double compared to conventional tapping methods.

The following example demonstrates how a strip-following tapping unit, running in a 12-in.-stroke press, can increase production rates:

Consider a ¼” in. thick part with a 3/8-16 tapped hole and 1 in. strip lift that needs approximately nine tap revolutions. A conventional tapping unit working from the bottom up with a 2:1 gear ratio (two revolutions per 1 in. of press stroke) requires the stripper to hold the material for approximately 4.5 in. This 4.5 in. window allows the press to run at 18 to 22 strokes/min. and still maintain the proper rpm on the tap. The same part with a strip-following tapping unit with a 1:1 gear ratio can run at 36 to 44 strokes/min. While maintaining the standard ¾ in. stripper travel, the strip-following tapping unit allows the tapping window to increase from 4.5 to 9 in., which reduces the rpm of the tap by half and doubles production rate.

Servo-Driven Tapping Units

Servo-driven tapping units allow the the threading operation to function independently of the press stroke. This capacity is particularly useful with large-diameter taps. Servo-driven units can tap for more than 180 degrees of the press cycle at specified rpm and rapid reverse in a shorter cycle time than conventional mechanical-driven units.

Servo-driven units find use in transfer presses, multi-slides and in high and low-stroke applications. Units can tap from the top down or bottom up and work in multi-tap applications. To take full advantage of a servo tapping unit, stripper travels generally are similar to or greater than those of conventional tapping units.

Copyright © 2012 GW Technologies Pty Ltd. Last modified: 07/29/12

Copyright © 2012 GW Technologies Pty Ltd.
Last modified: 07/29/12