Tolerance Stack-UpWhy tolerances add along a chain, and what statistical stacking assumes.Mechanical EngineeringTolerances along a chain of features add up, and theresulting gap can be far looser than any single one.Worst case: add them · Statistical: √(sum of squares)Four parts at ±0.1 eachWorst case ±0.4All at one limit.Same four, statisticalAbout ±0.2Root sum of squares.Need a tighter gapShorten the chainFewer joints, less stack.THE COMMON MISTAKE✗ Using the statistical method on a two-part stack✓ It needs many independent partsRoot sum of squares assumes several parts varying independently and normally.On a short chain, or a biased process, it under-predicts the spread.Better still, design so the stack does not matter: locate every part fromone datum rather than part to part.Tolerance Stack-Uplearnposters.com
Tolerance Stack-Up — printable engineering wall chart from LearnPosters. Free vector PDF, US Letter and A4.

What’s on the Tolerance Stack-Up poster

The rule, 3 worked examples, and the mistake everyone makes.

Better still, design so the stack does not matter: locate every part from one datum rather than part to part.

Questions about the Tolerance Stack-Up poster

What’s on the Tolerance Stack-Up poster?
The rule, 3 worked examples, and the mistake everyone makes. Tolerances along a chain of features add up, and the resulting gap can be far looser…; Worst case: add them · Statistical: √(sum of squares); Four parts at ±0.1 each = Worst case ±0.4; Same four, statistical = About ±0.2; Need a tighter gap = Shorten the chain; Common mistake: Using the statistical method on a two-part stack → It needs many inde…. Better still, design so the stack does not matter: locate every part from one datum rather than part to part.
Who is the Tolerance Stack-Up poster for?
Tolerance Stack-Up belongs to the Mechanical Engineering section rather than to a school year, because engineering is not something one grade owns. Anyone learning cad & drawing can pin it up — a beginner, a student mid-course, or someone revising years later.
When should you use the Tolerance Stack-Up poster?
Assemblies where several parts in a row decide one clearance or one gap. A wall chart earns its place by being glanceable from where the work is happening, so Tolerance Stack-Up belongs on the wall where that engineering work actually happens, within glancing distance, rather than filed away.
What other posters go with Tolerance Stack-Up?
Assembly Drawings, Auxiliary & Detail Views and Choosing Views sit alongside Tolerance Stack-Up in the Mechanical Engineering section. Printed together they make a wall rather than a single sheet, which is how a reference set actually gets used.Assembly DrawingsAuxiliary & Detail ViewsChoosing Views
Is the Tolerance Stack-Up poster free to download and print?
Yes. Tolerance Stack-Up downloads as a free PDF with no account, no email and no watermark, like everything else in the Mechanical Engineering section. Print as many copies as you like for a home, a classroom, a library or a tutoring group; reselling the file is the only thing the licence rules out.Read the licence
What size does the Tolerance Stack-Up poster print at?
Tolerance Stack-Up is a vector PDF laid out for US Letter, and prints on A4 with Fit to page — the same file, no separate download. Because every mark on it is drawn rather than photographed, it stays sharp enlarged to A3, A2 or A1 at a copy shop. Colour carries emphasis only, so a greyscale print of Tolerance Stack-Up loses nothing.Printing guide

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