Bostitch ARM - 163908

Bostitch 163908 — Arm, Upper Contact (original Bostitch contact arm) — a direct replacement contact-trip arm that secures into the tool’s contact assembly and engages the feed/trigger so the nailer will fire reliably.

Fits a range of Bostitch coil nailers — commonly listed for DPN90C and D31AD-3 and shown on related parts diagrams for F‑series and similar coil models.

The part is supplied individually as the upper contact arm used in the contact/feeding assembly; install it in the contact bracket where the existing worn or broken arm is removed to restore correct trip action.

If you’re stocking Bostitch parts for quick repairs, this 163908 upper contact arm is the small, replaceable component you’ll look for when a nailer’s contact trip stops engaging properly — a straightforward parts for power tools replacement that gets the tool back to work.