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2103-379 PTFE S/T BUP FDA

PTFE Back-Up Ring, 10.975 in ID x 0.21 CS, 55D, White, -65 to 500°F

Status
Out of Stock
Est. Ship Date
21 Oct 2026
Material
PTFE (Polytetrafluoroethylene)
Dash Size
379
Durometer
55 Shore D
Cross Section Type
Round
Color
White
Minimum Temperature
-65°F (-53.9°C)
Maximum Temperature
500°F (260°C)
Nominal Cross Section
3/16 inch
Nominal Inside Diameter
11 inch
Nominal Outside Diameter
11 3/8 inch
Unit of Measure
EA
SKU:
TST379

Product Specification

-
Ordered as TST379, this is an AS568-379 white PTFE (Teflon) 55 Shore D Back-Up Ring measuring an inside diameter of 10.975 in (278.77 mm), a cross section of 0.21 in (5.33 mm), and an outside diameter of 11.395 in (289.43 mm). The back-up ring allows a standard o-ring to operate at higher pressures than it could unsupported.

As a material, PTFE (Teflon) offers excellent dielectric properties and one of the lowest coefficients of friction of any solid. Expect good resistance to solvents, strong acids and bases, and steam. Service temperature is rated from -65°F (-53.9°C) through 500°F (260°C). It is not the right choice where molten alkali metals or elemental fluorine at temperature are present.

You will find this material specified across semiconductor fabrication, pharmaceutical and biotech, and laboratory equipment.

TST379 ships individually. Application requirements vary, so validate compatibility with your process conditions prior to installation. APG can cross-reference from an existing part number, a drawing or a physical sample if this size is not an exact match.
Item
TST379
Description
2103-379 PTFE S/T BUP FDA
Actual Cross Section
0.21 inch (5.33 mm)
Actual Inside Diameter
10.975 inch (278.77 mm)
Actual Outside Diameter
11.395 inch (289.43 mm)
FDA Compliant
No
Measurement System
Imperial
Metal Detectable
No
NSF Certified
No
Product Code
6002
Product Category
O-Rings - Backup Rings