Обший каталог Yamawa 2016 - 2017 - страница 795

Guide to Thread Forming Taps (Roll Taps)

Thread Forming Taps are the tools used for producing internal threads by a thread forming process. Currently, YAMAWA's Thread Forming Taps have

P1 P3 P5 a good reputation by being used in many areas. They are widely used along with the diversity of workpieces and with the change into miniaturization

P2 P4 P6 of workpieces. Followings are the characteristics and features of Thread Forming Taps (Roll Tap) which are not available with cutting taps.

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<Features of Roll Taps>

Tapping without producing chips. They are suitable for blind hole tapping. In producing internal threads with no chips, they save you a P1 time for chip disposal.

№2-56 UNC 53 70

GH2 Roll taps are stronger than cutting taps due to their design. The effect of fluteless design gives a large cross-section area to the tap, P1 and there is no worry of chip jamming, which makes Roll taps very tough against breakage.

№3-48 UNC 55 75 Roll taps produce excellent pitch diameter well within pitch diameter tolerances. Material deformation process produces the

GH2 internal threads with good surface finish as well as precise pitch diameter.

P1 P2 P3 High efficiency and tool life The configuration of the lobes at the crests of the tap threads makes high speed tapping possible and extends

№4-40 UNC 60 83 tool life compared with cutting type taps. The addition of a supplemental tap surface treatment, such as Oxidizing, Nitriding, TiN, and TiCN can

GH2 GH3 GH4 GH5 extend tool life 2 to 20 times over an uncoated (bright) tap performance. P1

№5-40 UNC 63 83 <Points to note during a Roll tapping operation>

GH2 ○ Tapping torque is 2 to 3 times larger than that of cutting type taps. ○Roll tapping is only applicable to materials producing stringy chips. ○The deviation of hole size before tapping should be about 5% of pitch. The control of hole size before tapping should be more severe than that of cutting type taps.

P2 P4 P6

○The selection of lubricants is important to prevent sticking or welding.

P3 P5 P7 ○

Burrs at the face of an internal thread are larger than those produced by cutting type taps. In some cases it is necessary to take additional countersink processing at the top of hole.

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○In the minor diameter of internal thread, U-shape form (Tine form) at the hole entrance can be seen. U-shape form is never seen when using cutting type taps.

P2 P3 P4

№6-32 UNC 68 93 <Selection of YAMAWA Roll Taps>

GH2 GH3 GH4 GH5 GH6 GH7 Types of Roll Taps YAMAWA produces various types of Roll Taps which include General purpose taps, Special purpose taps for non-ferrous and

P2 P3 P4 steel, as well as special purpose taps with surface treatment for the specified applications. To provide for longer tool life, specially developed

№8-32 UNC 71 96

GH2 GH3 GH4 GH5 GH6 GH7 premium materials are also used together with physical vapor coating deposition (PVD) such as TiN and TiCN. In particular, OL-RZ is superior product developed for dry machining with regards to tapping environment and performance.

P2 P3 P4 Tap Materials

№10-24 UNC 80 108 YAMAWA's standard tap material is SKH58 designed for improving torque, superior anti-friction properties as well as toughness.

GH3 GH5 GH6 GH7 To extend tool life, we use SKH56, or SKH10(Powder HSS) which is the best tap material for antifriction.

P2 Tolerance Class Using the datum 12.7μm in a step form, in accordance with ANSI standard GH class, we made up YAMAWA's G class system.

№12-24 UNC 82 110 The differences in materials being Roll tapped, as well as hole size, contribute to differences in thread forming. YAMAWA offers 2 to 3 oversized tap

GH3 tolerance classes in order to achieve the most suitable internal thread pitch diameter size.

P2 P3 P4 Chamfer length Chamfer lengths : 2 pitches for blind hole use and 4 pitches for through hole use. Basically 4 pitches have longer tool life than

1/4-20 UNC 90 123 2 pitches because force applied on one blade at 4 pitch chamfer is smaller than that at 2 pitch chamfer. However, it is difficult to say about tool life

GH3 GH5 GH6 GH7 in a few words because each different tapping condition influences the tool life.

P2 P3 P4

5/16-18 UNC 98 134 <Shape of internal threads and the ratio of thread engagement affected by bored hole diameter>

3/8-16 UNC 108 144

7/16-14 UNC 116 154 decreasing tap’s wear and damage.

GH3 GH5

P2 P3 P4 S50C, minor diameter of threads cut Aluminum, minor diameter of threads formed

1/2-13 UNC 121 165

GH3 GH5 GH7 M24x3 M25x2

P2 minor dia tolerance of internal threads minor dia tolerance of internal threads

9/16-12 UNC 128 172

GH3 20.752~ 21.252 22.835~ 23.210

P3 P4 Internal External Aluminum, internal threads formed Internal External

5/8-11 UNC 136 182 S50C internal threads cut

GH3 GH5 threads threads M25x2 threads thread

M24x3 bored hole size : 23.903 side

P3 P4 bored hole size : 20.652

3/4-10 UNC 144 195 minor diameter of finished internal threads : 22.723mm

minor dia tolerance of internal threads NG

GH3 GH5 minor dia tolerance of internal threads NG

thread engagement ratio : 103.1% P3 thread engagement ratio : 105.2%

7/8-9 UNC 154 207

GH4 Aluminum, internal threads formed S50C internal threads cut M25x2 M24x3 bored hole size : 24.042mm bored hole size : 21.000 minor diameter of finished internal threads : 23.067mm minor dia tolerance of internal threads: Middle

P2 P4 P6 P8 minor dia tolerance of internal threads : Middle

thread engagement ratio : 92.4% thread engagement ratio : 89.3%

P3 P5 P7 ⑤

⑤ Aluminum, internal threads formed S50C internal threads cut

210 220 230 240 M25x2

M24x3 bored hole size : 24.240mm bored hole size : 21.352 P4 minor diameter of finished internal threads : 23.462mm

1-8 UNC 167 223 minor dia tolerance of internal threads NG

minor dia tolerance of internal threads NG GH4 thread engagement ratio : 81.5% thread engagement ratio : 71.0%