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2103-255 PTFE S/T BUP FDA

PTFE Back-Up Ring, 5.609 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
255
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 5/8 inch
Nominal Outside Diameter
5 7/8 inch
Unit of Measure
EA
SKU:
TST255

Product Specification

-
Ordered as TST255, this is an AS568-255 white PTFE (Teflon) 55 Shore D Back-Up Ring with an inside diameter of 5.609 in (142.47 mm), a cross section of 0.139 in (3.53 mm), and an outside diameter of 5.887 in (149.53 mm). The back-up ring allows a standard o-ring to operate at higher pressures than it could unsupported.

The compound resists oxidizing media, strong acids and bases, and nearly all industrial chemicals. That behavior comes from the compound itself: PTFE (Teflon) delivers one of the lowest coefficients of friction of any solid and non-stick, non-contaminating surface characteristics. The material carries a published service range of -65°F (-53.9°C) to 500°F (260°C). Exposure to elemental fluorine at temperature or molten alkali metals will shorten service life.

It sees regular use in pharmaceutical and biotech, chemical processing, and food and beverage.

Reference part number TST255 when ordering; the item is sold individually. Nominal inside diameter is listed as 5 5/8 inch. Review your operating media and conditions against this specification before installation. Not finding the exact configuration you need? APG cross-references from prints, samples and competitor part numbers.
Item
TST255
Description
2103-255 PTFE S/T BUP FDA
Actual Cross Section
0.139 inch (3.53 mm)
Actual Inside Diameter
5.609 inch (142.47 mm)
Actual Outside Diameter
5.887 inch (149.53 mm)
FDA Compliant
No
Measurement System
Imperial
Metal Detectable
No
NSF Certified
No
Product Code
6002
Product Category
O-Rings - Backup Rings