# FitCheck: Hole Sizes & Fits — Screws, bearings & inserts

> Screws, bearings & inserts (iPhone/iPad app by Matthew Johnson.)

- Source: https://appshunter.io/ios/app/fitcheck-hole-sizes-and-fits/id6790169959 (this page in markdown: same URL + `.md`)
- Developer: [Matthew Johnson](https://appshunter.io/developer/1627360462)
- Category: Utilities, Productivity
- Price: Free with in-app purchases
- Age rating: 4+
- Requires: iOS 15.0 · 21 MB
- Languages: American English
- Released: 2026-07-24
- Data updated: 2026-08-18
- User reviews in markdown: https://appshunter.io/ios/app/fitcheck-hole-sizes-and-fits/id6790169959/reviews.md

## What is FitCheck?

"What size hole do I need?" That's the question FitCheck answers — for screws, bearings, and hex nuts. Enter a size — M5-0.8, #8-32, 1/4-20, or a 608 bearing - and you get the hole or pocket to model, whether you're drilling, tapping, boring a bearing seat, or printing the part.

For makers, hobbyists, and anyone who designs and builds:
• Clearance holes and tap-drill sizes for every screw and bolt in the catalog
• Bearing pockets: press, slip and loose fits for machined and 3D printed seats
• Hex-nut pockets in three clearances (snug / normal / loose)
• 3D-printed screw holes in three grades (close / normal / free)
• Heat-set insert holes, with pocket depths matched to your insert length
• An inch-to-mm converter and fraction ruler for caliper readings
• Cross-section diagrams that show the fit

The part a chart can't do: your machine. Calibrate each printer or mill once, and every size — screw, bearing, or nut — comes out corrected for that machine's measured error. Less re-printing and re-milling to get a fit right.

It works completely offline. No accounts, no ads, and no tracking — all reference data lives on your device.

Machine calibration is free to try. FitCheck Pro — a one-time purchase, no subscription — keeps your calibrated machines saved, so every lookup comes out corrected without redoing setup.

This app is a reference only — always check against your own test parts before you cut.

## Pricing and in-app purchases

Base price: Free.

**One-time purchases**

| Purchase | Price | Type |
| --- | --- | --- |
| FitCheck Pro | $4.99 | one-time |



## Version history (last 3 releases)

### 1.3 — 2026-08-14

Fits that work on any printer — and calibration that's truer everywhere else.
• NEW Robust pockets: tested crush-rib pockets for 608 bearings and M5 nuts. They grip uncalibrated (and more sizes coming soon)
• Calibration goes further: hex flats and big bores measure separately, so nut pockets stay snug and bearing seats stop over-correcting.
• Copy your calibrated number straight into your slicer.
• Corrected sizes now show what they should actually print at.

### 1.2 — 2026-08-10

Cleaner, faster result card:
• Sections now collapse — tap to open just the one you need, and each shows its key dia at a glance.
• Tap and hold any dimension to copy the value.
• Hole diameters are marked with Ø - better clarity and quicker value understanding
• Browse a grouped list of fasteners, instead of just searching
• Shareable exports of the fastener size and its attributes.
• Heat-set inserts: pick your insert series (e.g. VORON) on supported sizes.

Big fit-reference update:
• Bearings: look up 608, 625, F695 & more — press, slip & loose pocket sizes for machined seats and printed pockets.
• Hex nuts are now their own lookup, with 3 pocket clearances (snug / normal / loose)
• Screws: new "Normal" printed clearance grade + head-pocket recess sizes.

### 1.0 — 2026-07-25

No release notes.

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*Data collected daily from the US App Store and indexed by [AppsHunter](https://appshunter.io/). User reviews are verbatim App Store reviews. Ratings, prices and chart positions refresh continuously; this snapshot is from 2026-08-18.*