4.4.3 STD vs. VACU

4.4.3   concept

Finger inserts seat in one of two ways — STD (Standard) or VACU (Vacuum). The insert type you record on the sheet (see 4.4.2) tells Spectre Cloud how the hole is drilled. This page explains the difference. For the OD-sizing concept, see 4.1.6.

📐 STD (Standard)

Standard inserts are press-fit: the hole is drilled to the insert's OD, at full depth, and the insert is pressed in and held by friction against the ball's coverstock.

• ✅ Drill bit size equals the insert's published OD — a direct, one-to-one match, full depth.
• ✅ A correct STD fit presses in with firm hand pressure or a seating tool — it shouldn't drop in freely or need excessive force.
• ❌ Never undersize an STD hole — a too-tight press-fit risks cracking the ball surface.

📐 VACU (Vacuum)

VACU inserts are drilled in two diameters so the insert has room to expand:

1. Drill the top portion at the size shown on the spec sheet.
2. Drill that top portion 1" deep.
3. Continue to the insert's actual OD for the rest of the depth.

The oversized top forms a pocket — a void where the insert doesn't touch the surrounding ball wall — giving the insert room to expand.

• ✅ The spec-sheet OD for a VACU insert is the top-portion (pocket) size, not the insert's body OD.
• ✅ The deeper portion is drilled to the insert's actual OD, exactly like a STD hole.
• ❌ Drilling the whole hole at one size removes the pocket entirely and defeats the VACU fit.

📊 STD vs. VACU

Related Sections

• 4.4.2 — Finger inserts (recording type, size, OD)
• 4.1.6 — Insert OD concept: STD vs. VACU, insert size vs. OD
• 2.6.6 — Autofill Insert OD

Tip: The most common VACU error is drilling the whole hole at one size. Remember it's two cuts — the spec-sheet size for the first inch to form the pocket, then the insert's actual OD to depth.