# tolerances, machining and cost

• 01-17-2018, 08:23 PM
Ayien
tolerances, machining and cost
Guys,
I make a bar to have clearance fit into a slot. The bar is X+0/-.0010" (eg: 1.0000 +0/-.0010" , which give a tolerance of .0010"). Now, the slot size is either (a) X+.0010/+.0002" (tol= .0008") or (b) X+.0010/+.0005" (tol=.0005").
Q: which tolerance fit best, easier machining process and cost effective?TQ
• 01-17-2018, 10:22 PM
Kelly Bramble
The variation of + or - is meaningless, we can rewrite a tolerance variation anyway we choose relative to the nominal size.

What matters is the total tolerance variation relative to the material, size, target manufacturing process, and associated target costing. Your tolerances specified are achievable and fit is determined by the clearance of the completed parts.

See: [url]https://www.engineersedge.com/general_tolerances.htm[/url]
• 01-18-2018, 03:56 AM
ridvansteel
Here you can find an exceptional tolerance value.
[url]https://www.engineersedge.com/iso_tolerance.htm[/url]
• 01-18-2018, 08:17 AM
Kelly Bramble
[QUOTE=ridvansteel;14507]Here you can find an exceptional tolerance value.
[URL]https://www.engineersedge.com/iso_tolerance.htm[/URL][/QUOTE]

And even better [url]https://www.engineersedge.com/calculators/mechanical-tolerances/table_shaft_tolerances.htm[/url]
• 01-18-2018, 11:00 PM
Ayien
thanks guys,

I need to explain to some guys here at my place that X+.0010/+.0005inch is tighter than X+.0010/+.0002inch as the former tolerance is .0005" and the later is .0008" This means that the later dimension is preferable by machinist.
Am I suggest the correct statement?