Every drawing should include all the information… however, it is not always clear unless you know...

Every drawing should include all the information… however, it is not always clear

unless you know what you are seeing.

L. Tatro CHSE 2011

L. Tatro CHSE 2011

#X: This means that this

applies throughout the drawing ___# of times.

This means diameter

This means centerline

This means Counterbore (a square cut oversized hole symmetrically around a smaller through hole

This means depth. This will be given when a hole, or counterbore does not go through the entire part.

This means countersink. When a hole has an interior chamfer this symbol is used.

8 2O

Along with a countersink symbol, a degree value is given for the tapered angle.

17.08 When seeing a set of numbers 17.25 stacked, this is used to give a acceptable range (tolerance).

L. Tatro CHSE 2011

R This means radius

TYP This means typical and is used when a drawing has a situation that repeats itself and is constant.

EQL SP Used when the distance between hole or features have a repeating value. Typically used in polar dimensioning .

BC means bolt circle and is used when a circular centerline is used to make the center locations of a bolt pattern.

L. Tatro CHSE 2011

This segment will help you identify and understand many of the terms used in the drafting/machining

industry for specific features.

Fillet: A rounded interior blend between surfaces.

Round: A rounded exterior blend between surfaces.

Counterbore: A cylindrical recess around a hole, usually to receive a bolt head or nut.

Countersink: A conical shaped recess around a hole, usually to receive a tapered screw head.

Spotface: A shallow recess like a counterbore, used to provide a good bearing surface for a fastener.

Boss: A short raised protrusion above the surface of a part, often used to provide a strong flat bearing surface. Bos

s

Lug: A flat or round tab protruding from a surface usually to provide a method for attachment.

Flange: A flattened collar or rim around a cylindrical part to allow for attachment.

Chamfer: An angled surface, used on cylinders to make them easier to start.

Flange

Lug

Neck: A small groove cut around the diameter of a cylinder or hub to receive a key, used to attach hubs, gears, and other parts to a cylinder so they won’t turn on it

Keyway : A shaped depression cut along the axis of a cylinder to receive a key (When mating two parts to prevent rotation).

Neck

Keyway

Knurl: A pattern form on a surface to provide for better gripping or more surface area for attachment, often used on knobs and tool handles.

Bushing: A hollow cylinder that is often used as a protective sleeve or guide, or as a bearing.

Rib: Like a boss, a rib is used internally to add strength to, or between features.

RIB

Self Quiz…. Left click to see the feature name in order 1

2

3

4

5

6

7

8

9

1011

12

13