Gesello – Metalwork Handbook
Fits, threads, CNC & more
Free · In‑App Purchases · Designed for iPad. Not verified for macOS.
The technical handbook that does the maths: enter a value, get the result with sketch and calculation steps. For metalworking, mechatronics and the workshop – offline.
The technical handbook that does the maths. Fit, thread, spindle speed or hardening temperature: enter a value – Gesello calculates your case with a sketch to scale and the calculation steps. Offline, no account, no ads. Metric, based on ISO.
WHY GESELLO?
• Calculated, not just looked up: ISO fits and threads come from formulas, not tables – for every nominal size and every pitch.
• Every result with sketch, formula and calculation steps – ideal for learning and for checking.
• Share with one tap: a clear text with a link that opens Gesello exactly where you were.
• Made for machinists, toolmakers, fitters, metalworkers, mechatronics technicians and all technical trades – in training, at technical college and in the workshop.
INCLUDED FOR FREE
• ISO tolerances and fits: limits of size, clearance, interference, transition fits, hole-basis and shaft-basis systems
• General tolerances for linear sizes, angles, radii and chamfers
• Geometrical tolerances with explanation and inspection guide
• Threads: coarse, fine, inch and special threads, tap drill, blind hole depth, thread turning with infeed per pass, thread milling
• Screws: tightening torque and preload by property class (8.8, 10.9, 12.9), engagement length, strap clamps
• Cutting data for drilling, reaming, turning, milling and grinding: spindle speed, feed, cutting speed, machining time, milling path, cutting force and power – with the speed steps of your own machine
• Surfaces: convert Rz to Ra, theoretical roughness for turning and milling
• Weight calculator for round, square, hexagon, tube, flat and sections – also straight from the stock designation
• Widths across flats, technical mathematics, triangles, unit conversion
• CNC (DIN/PAL): all G and M codes for turning and milling with sketches, face milling helper with a ready NC program
• Drawing symbols, workpiece edges and threads in technical drawings, with typical mistakes
• Standard parts: parallel keys, retaining rings and O-rings with groove dimensions
• Taper turning: compound slide angle, Morse and steep tapers, tailstock offset
• Practice: exercises with worked solutions, from the vernier caliper to fits
GESELLO PRO – BUY ONCE, NO SUBSCRIPTION
• Measuring & inspection: read calipers and micrometers, choose gauges, inspection plan, statistics, gauge block combinations
• Materials: decode steel names and material numbers, cast iron, aluminium, copper, plastics, properties
• Heat treatment: hardening temperature from the steel name, iron-carbon diagram, annealing, hardening, quenching and tempering, case hardening, nitriding, temper colours
• Convert hardness: HRC, HV, HB and tensile strength
• Grinding wheels: read the designation, maximum speed, check flanges, mount safely
• Control engineering: pneumatic and hydraulic symbols, directional valve builder, logic with truth table, displacement-step diagram, GRAFCET, electropneumatics, timers
• Hydraulics and pneumatics: piston force, air consumption, press, lines
• Production planning: process plans for turned parts, milled parts, hole patterns and assembly with cutting data and times, reorder steps by dragging, share as PDF; manufacturing cost per part and batch
• Indexable inserts: decode designations, recognise wear, troubleshooting for chatter or rough surfaces
• Bolt circles, hole rows and dividing head, counterbores and centre holes
• Bending: blank length, bend deduction, minimum bend radius, tubes, sections, rolling, flat patterns, shearing, press brake
• Tolerance stacks, welding, drives, coolant
• CNC cycles with input mask and a ready NC block
• Scientific calculator on every page, with real fractions
YOUR DATA STAYS WITH YOU
No account, no ads, no tracking. Gesello calculates directly on the device and works without internet – on the shop floor just as well as in the basement of the training centre.
Questions or ideas? Write to dev@gesello.app – Gesello is constantly being extended.
Ratings & Reviews
- This app hasn’t received enough ratings or reviews to display an overview.
New: exam trainer “Fit for the exam” with exam-style questions, worked solutions and standard-compliant sketches – question of the day, quick quiz per topic, flashcards and error reporting. Theory right in the module: threads, fits, cutting data, materials and hardness explain their values and have their own knowledge pages. New practice topics with exam tasks. Also: first and third angle projection, protection classes, rivet length.
The developer, Clemens Riemer, indicated that the app’s privacy practices may include handling of data as described below. For more information, see the developer’s privacy policy .
Data Linked to You
The following data may be collected and linked to your identity:
- Contact Info
- User Content
Data Not Linked to You
The following data may be collected but it is not linked to your identity:
- Identifiers
Accessibility
The developer has not yet indicated which accessibility features this app supports. Learn More
Information
- Seller
- Clemens Riemer
- Size
- 68.6 MB
- Category
- Reference
- Compatibility
Requires iOS 15.0 or later.
- iPhone
Requires iOS 15.0 or later. - iPad
Requires iPadOS 15.0 or later. - iPod touch
Requires iOS 15.0 or later. - Mac
Requires macOS 12.0 or later and a Mac with Apple M1 chip or later.
- iPhone
- Languages
English and 17 more
- English, Croatian, Czech, Danish, Dutch, French, German, Hungarian, Italian, Japanese, Polish, Portuguese, Romanian, Russian, Simplified Chinese, Spanish, Swedish, Turkish
- Age Rating
4+
- 4+
- In-App Purchases
Yes
- Gesello Pro $8.99
- Copyright
- © 2026 Clemens Riemer