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 then the stamping
operation. The following are some of the features of the In-die tapping heads:
- Press speed up to 250 strokes per minute
- Compact design
- Simple installation
- High torque driver extends service life
- Quick change twist lock lead screw assembly
- Change taps in seconds while in the press
- Use 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
- Change from die to die in minutes
- Capacity 2-56 to 1-1/4"-12 (or metric
equivalent)
- Made in the USA
Multiple Spindle and Special In-Die 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. With the twist lock lead screw assembly any
combination of pitch and tap diameters can be combined in a single
multiple unit. The TH-55 high torque driver can tap as many as eight
5/16"- 18 holes in a single tapped part.
We specialize in custom in-die tapping units built to customers
specifications. Whether a tapped part has three #4-40 or five 3/8"-
16 tapped holes, we will build a top down, bottom up, or rapid
advance multiple spindle in-die tapping unit to fit your
requirements while keeping costs to a minimum.
Strip-Following Tapping Unit
A new self-contained strip-following in-die tapper was introduced at
METALFORM’03 in
Chicago. This unit increases tapping production rates while maintaining standard stripper lengths, which greatly reduces tooling
costs. 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 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 as 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. Also, with a conventional tapper, the 4.5 in. of stripper travel requires the use of nitrogen cylinders as
opposed to conventional die springs.
Servo-Driven Tapping Units
The primary advantage of using a servo-driven tapping unit: The threading operation functions
independently of the press stroke, particularly useful with large-diameter taps.Servo-driven units can tap for
more than 180 deg. Of the press cycle at specified rpm and rapid reverse in a shorter cycle time than can a conventional mechanical-driven unit.
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.
In the past, cost was the major disadvantage to servo-driven tapping units; a servo-driven tapping unit
might have cost two to three times that of a conventional unit, and on many high-speed applications a servo-driven unit can’t match the performance of a
mechanical unit. However, some of today’s newly designed servo tapping units are much more competitively priced.
