Общий каталог Yamawa 2021 - страница 701

19. The mechanism for a tap to cut oversize on an internal thread

1. Run out, misalignment and tap doesn’t cut perpendicular into holes Over-cutting at radial direction

SP

and checked when idle The use of adjustable running. holder with floating features will reduce this Lateral force problem.

Solutions

PO

misalignment

ST Run out

Excessive cutting in radial direction causes oversized internal threads. Since tapping proceeds along bored hole, in the depth of hole, oversize cutting is minimized, that is, oversize cutting in the beginning of the hole and ROLL normal cutting in the depth of the hole.

Excessive-cutting in the radial direction Normal internal threads

CARBIDE

Not Go gauge

of the bore threads

HAND

TAPS

2. Using a tap not suitable for the operation or a tap with dull Over-cutting caused by galling and excess cutting

cutting edge may cause galling and result in over-cutting.

EG (STI)

Using an incorrect tap for a specific workpiece material Tapping process with dull edge can cause problems

Wear Welding Chipping

Select the correct Tap Flank SPECIAL Straight fluted tap THREADS, Spiral fluted tap GAUGES Spiral pointed tap

• Roll tap

Parallel

[Wear] wear [Welding] [Chipping]

THREAD Selection of correct taps suitable for material being tapped is strongly recommended. Solution: Proper use of cutting oil, confirmation of a constant for tool life MILLS

DIES Torn threads occur on the thread flanks. If this Incomplete

thread situation gets worse, there occur large thread collapses or incomplete threads finally bringing out oversized internal threads. Incomplete

Depending on the condition of collapsed threads thread CENTER such trouble tends to occur discontinuously as NOT-GO gouge enters. DRILLS Special attention needs to be taken so that random inspection should not miss this kind of trouble. Incomplete thread

Over-cutting caused by galling and excess feeding

Not Go gauge