Weldon 還是 Whistle Notch？為什麼這兩種柄不能互換

兩種側向鎖緊的柄、兩種平面，以及現場真的會發生的錯誤：把 whistle notch 的刀具裝進 Weldon 刀把，或者反過來。它們像到裝得進去，又差到會出事。

Weldon —— 與軸線平行的平面，用止付螺絲鎖緊。DIN 6359 / 1835B

Whistle notch —— 帶 2° 斜度的平面，鎖緊時把刀具往座面拉回。DIN 1835E

一張表看差別

Weldon, DIN 1835-B	The flat is parallel to the axis. The set screw pushes sideways onto the flat. Axial position is set by how far you push the tool in.
Whistle notch, DIN 1835-E	The flat is inclined — Mongtec cuts it at 2°. As the screw tightens it also pulls the tool back against the seat, so the axial position is defined by the holder, not by the operator.

Weldon, DIN 1835-B

The flat is parallel to the axis. The set screw pushes sideways onto the flat. Axial position is set by how far you push the tool in.

Whistle notch, DIN 1835-E

The flat is inclined — Mongtec cuts it at 2°. As the screw tightens it also pulls the tool back against the seat, so the axial position is defined by the holder, not by the operator.

混用會發生什麼事

whistle notch 刀具裝進 Weldon 刀把：止付螺絲只會接觸到斜面的一個邊緣。接觸面積塌掉，螺絲可能在刀柄上壓出痕跡，而刀具在軸向負載下會慢慢跑出來。

Weldon 刀具裝進 whistle notch 刀把：螺絲頂在一個平行平面上，沒有往回拉的效果。輕切削是撐得住，但你失去的正是當初選 whistle notch 的理由 —— 軸向重複性。

該選哪一種

Weldon 用在粗銑、大側向負載，以及任何你希望連接方式越單純越好的場合。它是現場最常見的柄。

whistle notch 用在換刀之間軸向位置很重要的場合 —— 階梯鑽孔、深度要求嚴格的挖槽，或任何刀具跑出零點幾毫米就會讓工件報廢的加工。

Mongtec 的型號範圍

Weldon	ø6 to ø50 mm on BT, BBT and HSK-A tapers. Coolant-through version available — the article number ends in K.
Whistle notch	ø6 to ø40 mm, flat at 2°.
Set screws	One screw up to ø20 mm; two screws from ø25 mm upward.

Weldon

ø6 to ø50 mm on BT, BBT and HSK-A tapers. Coolant-through version available — the article number ends in K.

Whistle notch

ø6 to ø40 mm, flat at 2°.

Set screws

One screw up to ø20 mm; two screws from ø25 mm upward.

如果你不確定手上是哪一種

拿一把直尺貼著那個平面。整段都貼平，就是 Weldon；有一端翹起來，就是 whistle notch。邊界不好判斷就拍張照片給我們 —— 我們寧可先確認，也不要你收到錯的刀把。