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203 PTFE SOLID BACKUP RING FDA

PTFE Back-Up Ring, 0.296 in ID x 0.139 CS, 55D, White, -65 to 500°F

Status
Out of Stock
Est. Ship Date
21 Oct 2026
Material
PTFE (Polytetrafluoroethylene)
Dash Size
203
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
1/8 inch
Nominal Inside Diameter
5/16 inch
Nominal Outside Diameter
9/16 inch
Unit of Measure
EA
SKU:
TST203SO

Product Specification

-
APG stocks the TST203SO, an AS568-203 white PTFE (Teflon) 55 Shore D Back-Up Ring measuring an inside diameter of 0.296 in (7.52 mm), a cross section of 0.139 in (3.53 mm), and an outside diameter of 0.574 in (14.58 mm). A back-up ring allows a standard o-ring to operate at higher pressures than it could unsupported.

This material stands up to strong acids and bases, solvents, and oxidizing media. That behavior comes from the compound itself: PTFE (Teflon) is specified for a very wide continuous service temperature range and non-stick, non-contaminating surface characteristics. Continuous operating temperature is published at -65°F (-53.9°C) to 500°F (260°C). It is not the right choice where service requiring elastic recovery or elemental fluorine at temperature are present.

Typical settings include food and beverage, aggressive-media pipelines, and semiconductor fabrication.

Stocked as TST203SO and sold individually. Nominal inside diameter is listed as 5/16 inch. Review your operating media and conditions against this specification before installation. For a size or compound outside the standard catalog, APG can quote from a print or sample.
Item
TST203SO
Description
203 PTFE SOLID BACKUP RING FDA
Actual Cross Section
0.139 inch (3.53 mm)
Actual Inside Diameter
0.296 inch (7.52 mm)
Actual Outside Diameter
0.574 inch (14.58 mm)
FDA Compliant
No
Measurement System
Imperial
Metal Detectable
No
NSF Certified
No
Product Code
6002
Product Category
O-Rings - Backup Rings