LittleMachineShop.com is the premier source of tooling, 
parts, and accessories for bench top machinists.  
Contact Us (800) 981 9663
Your Orders
Cart  Cart
   

On Sale
Value Packs
New Products
All Products
Catalog
Store Location
Outlet Store

 
Have you seen?
Dial Indicator, 1" x 0.001", Professional Grade
 
Most Popular of
Lathe Chucks
Lathe Chuck, 4-Jaw 4" with Adapter
Lathe Chuck, 4-Jaw 4" with Adapter
Additional popular items
 

Machinist's Calculator
Our mobile app; read this with your phone.
lmscnc.com/calc

 
Onliine Metals  

 

  

Symbols Used on Our Drawings

These symbols are used on the Mechanical Models engine drawings as well as on many other drawings.

Identifies a surface
Means that the indicated surface should be parallel to surface A within 0.10 mm
Means the bore should be perpendicular to surface A within 0.05 mm
Means that the diameter should be concentric to diameter A within 0.03 mm
Specifies the diameter, in mm
Specifies a thread. M3 means a 3 mm standard thread. 7H means a standard class of fit (that is, make it fit). The pitch for standard metric threads are as follows:
Diameter   Pitch
3 mm   0.5 mm
4 mm   0.7 mm
5 mm   0.8 mm
6 mm   1.0 mm
8 mm   1.25 mm
Indicates a surface finish of 1.6 micrometers, the same as 63 micro inches. That's a good turned surface.
Indicates surface finish of 1.6 micrometers. The circle indicates that you should not remove any material, simply use the size and finish that is provided.

 

Contact Us / Company Info / Privacy Policy / Warranty / Terms & Conditions / Payment Options / Shipping Rates & Policies
Copyright © 2007-2018 LittleMachineShop.com
 
Phone: (800) 981-9663