Product/Service

Screw Standards

Source: Flite Technology Inc.
The Society of Plastics Industry's Machinery Component Manufacturers Division

Single Screw

Dimensional Guideline Recommendations

The following recommendations for single screws for

The Society of Plastics Industry's Machinery Component Manufacturers Division

Single Screw

Dimensional Guideline Recommendations

The following recommendations for single screws for extrusion/injection machinery have been prepared as a guide to manufacturers and processors. These standards provide working tolerances that produce effective performance with economy of manufacture.

LENGTHS, DEPTHS & WIDTHS

DIMENSION
DESCRIPTION
 ENGLISH UNITS
METRIC UNITS
 RANGE  TOLERANCE
  RANGE
   TOLERANCE
I.Most Linear Dimensions
 To 12"

12-60"

60-120"

120-200"

Over 200"

 +/- .010"

+/- .030"

+/- .045"

+/- .060"

+/- .090"
To 300mm

300-1500mm

1500-3000mm

3000-5000mm

over 5000mm

 +/- .25mm

+/- .75mm

+/- 1.00mm

+/- 1.50 mm

+/- 2.25mm
II.Flight Width
To .500"

.500-1.000"

Over 1.000"

 +/- .015"

+/- .020"

+/- .030"

   To 12mm

12-25mm

over 25mm

 +/- .38mm

+/- .50mm

+/- .75mm
III.Channel Depth To .100"

.100-.500"

Over .500"

 +/- .003"

+/- .007"

+/- .012"

 To 2.5mm

2.5-.13.0mm

over 13.0mm

 +/- .08mm

+/- .18mm

+/- .30mm
IV. Barrier Flight Depth To 6.0" Dia.

Over 6.0" Dia.

 +/- .002"

+/- .003"

 +/- .05mm

+/- .075mm
V.Section Length All Sizes +/- 1/8 turn +/- 1/8 turn
VI. Keyways All Sizes Depth +/- .005" depth +/- .13 mm
VII. Hollowbores All Sizes Length +/- .030" Length +/- .76mm
VIII. Thread Pilots

*Injection Extrusion

 All Sizes

All Sizes

 Length +/- .005"

Length +/- .015"

 Length +/- .13mm

Length +/- .4mm
*This should particularly be observed for screws filled with non-return valves.

DIAMETERS
DIMENSION ENGLISH UNITS METRIC UNITS
DESCRIPTION RANGE TOLERANCE RANGE TOLERANCE
I. Flight & Bearings

(Hub) Diameters

 To 6.0"

Over 6.0"

 +/- .000-.002"

+/- .000-.004"

 To 150mm

over 150mm

 +/- .00-.05mm

+/- .00-.10mm
II. Shank Diameters

(Drive Fit)

 All Sizes +/- .0-.002" All Sizes +/- .00-.50mm
III. Hollowbores To 3"

3 to 6"

over 6"

 +/- .020"

+/- .040"

+/- .060"

 To 75mm

75-150mm

over 150mm

 + .5mm

+/- 1.0mm

+/-1.5mm
IV. Thread Pilots

*Injection Extrusion

 All Sizes

All Sizes

 Dia + .001-.000"

Dia + .002-.000"

 Dia + .025-.000mm

Dia + .050-.000mm
*This should particularly be observed for screws fitted with back-flow valves.

Flite Technology Inc., 408 A Hawk Street. Tel: 800-327-9310; Fax: 321-631-2331.