Quickly solve trades math problems with this convenient App!

Right Angle calculations-Quickly calculate the dimensions and area of a right angle triangle.

Oblique Triangle calculations-Quickly calculate the dimensions and area of an oblique triangle.

Speeds and Feeds - Quickly calculate cutting Speeds and Feeds for drills, milling cutters, and lathe workpieces. Calculate between RPM and Feet-Per-Minute or Meters-Per-Minute, and between Feed-Per-Rev and Feed-Per-Minute. Drill Charts and Materials List are usable right in the function.

Counter Sinks & Drill Points-Calculate drill point and countersink depths. Drill Charts usable right in the function.

Bolt Circles - Calculate X-Y coordinates for equally spaced bolts. You can make the center of the circle any coordinate you need, and place the first hole at any angle.

Sine Bar - Quickly and accurately calculate precision block stack or angle for use with sine bars or sine plates.

Thread Measure - Quickly make all the calculations required to measure screw threads using the 3 wire method.

Drill Charts-Quickly lookup Decimal conversions of Inch based Number & Letter Drills, and Tapping Charts for UN & ISO Metric, Cutting, and Coldform (roll) taps. Use the Drill Charts right in the Speeds & Feeds and C'Sink & Drill Point Functions.

Materials List--Material list containing starting cutting speeds for over 200 materials. Use the Materials List right in the Speeds & Feeds Function.

All calculations can switch between imperial and metric with the touch of a button.

Uses an attractive graphical diagram background for easy answer references! No more text boxes and labels! Automatically makes the calculation once enough information is entered!

Universal App! Compatible with iPhone, iPod Touch, and iPad!

What’s New

Version 2.3

3 Wire Thread Measure Function Added

Quickly make all the calculations required to measure screw threads using the 3 wire method!

Whitworth (BSW), UN, ISO Metric, Trapezoidal, Acme, and Stub Acme. Uses formulas that give very accurate results for lead (helix) angles generated by single start threads. When measuring threads with larger angles, such as UN or ISO Metric, results will be highly accurate for threads with lead angles up to ten degrees.

Just enter the minimum required info and your answers instantly appear!

Ratings and Reviews

3.8 out of 5
19 Ratings

19 Ratings

SomeDumbNicknameNoAlreadyTaken ,

Description lies

I bought this app for one reason, to calculate lathe speeds and feeds, something this app claims to do. After purchasing it, I found out there isn’t a section of the app even related to lathe speeds and feeds. There is a section for calculating drill speeds and feeds, but not one for lathe work.

In addition, the interface is clunky. Its not really apparent what you can click on for settings, and the ones that are active require you to hold your finger down for a half second vs. just tapping.

This app doesn’t cost much, which is good, because it doesn’t seem to be worth much.

I-evan ,

Ripped off

While the advertisement for this app seems quite inclusive, it's falsely advertised. It shows features that this app has that are not present, including taper calculations. Once downloaded this app does not deliver. Apple should look into this and refund our money.

Flash McGoofy ,

Machinists calculator

Works well for what I bought it for. Creating bolt circles.


App Owl Development
21.3 MB

Requires iOS 6.0 or later. Compatible with iPhone, iPad, and iPod touch.



Age Rating
Rated 4+
© App Owl Development


  • Family Sharing

    With Family Sharing set up, up to six family members can use this app.

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