welding unit 7

Shape description

Visible lines are used to show the visible features of a part. Views are used to show the length, width, and thickness of a part.

Size description

A properly dimensioned drawing includes all dimensions needed to give a complete size description of the product.

Dual dimensioned Print

Has both English and metric values.

Material Specification

Gives the exact grade or substance ex. AISI 1020 steel.

Tolerance

The entire amount of variance allowed in the size of a part or object.

Bilateral tolerance

When the tolerance is plus and minus and the variance is in both directions.

Unilateral Tolerance

When the tolerance permitted is in one direction only, either plus or minus.

Work order

indicates the total number of units to be manufactured. Helps to find the most economically efficient way to manufacture the part.

Routing sheet/Shop Traveler

Used to list the specific processes required to make the part, sub-assembly, or assembly. The list is in order of operation and may include estimated productuion times, process numbers, and inspection requirements.

Scale of drawing

one half size (1:2), twice the actual size (2:1), actual size (1:1).

Finish

general finish requirements ex. sand blasting, plating, painting, etc.

Revisions

indicates what changes have been made to the original drawing.

Next Assembly/application

provides the next step in the manufacturing and assembly operations.

Drawing title

Tells the welder the correct name of the part

Print number/identifying number

For your convenience in filing and locating drawings.

Heat Treatment

Includes a number of processes involving the controlled heating and cooling of a metal or alloy to obtain desirable changes in its physical characteristics. Can improve toughness, hardness, and resistance to shock.

Anneal

soften metals to make them easier to work.

Notes

Information not included in the title block or dimensioned views, but pertinent to the manufacture or assembly of the part.

Print sheet size

The size of the paper the print is drawn on. Size A (8.5 x 11) or (9 x 12) Size E (34 x 44) or (36 x 48)

Zoning

A technique used to aid in locating details on larger size drawings.

Security Classification

Top secret, secret, confidential, or restricted drawings. The type of classification is noted on the top of the sheet and below the title block.

Dimensioning Symbols

American National Standards Institute (ANSI). Current practice uses symbols and old practice writes out things like depth and countersink.