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2103-359 PTFE S/T BUP FDA

PTFE Back-Up Ring, 5.725 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
359
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
5 3/4 inch
Nominal Outside Diameter
6 1/8 inch
Unit of Measure
EA
SKU:
TST359

Product Specification

-
This back-up ring is supplied in AS568-359 white PTFE (Teflon) 55 Shore D built to an inside diameter of 5.725 in (145.42 mm), a cross section of 0.21 in (5.33 mm), and an outside diameter of 6.145 in (156.08 mm), catalogued under part number TST359. It allows a standard o-ring to operate at higher pressures than it could unsupported.

PTFE (Teflon) is specified for excellent dielectric properties and non-stick, non-contaminating surface characteristics. The compound resists strong acids and bases, solvents, and nearly all industrial chemicals. Continuous operating temperature is published at -65°F (-53.9°C) to 500°F (260°C).

Maintenance and OEM teams specify it across chemical processing, pharmaceutical and biotech, and aggressive-media pipelines.

TST359 ships individually. Nominal inside diameter is listed as 5 3/4 inch. Application requirements vary, so validate compatibility with your process conditions prior to installation. Not finding the exact configuration you need? APG cross-references from prints, samples and competitor part numbers.
Item
TST359
Description
2103-359 PTFE S/T BUP FDA
Actual Cross Section
0.21 inch (5.33 mm)
Actual Inside Diameter
5.725 inch (145.42 mm)
Actual Outside Diameter
6.145 inch (156.08 mm)
FDA Compliant
No
Measurement System
Imperial
Metal Detectable
No
NSF Certified
No
Product Code
6002
Product Category
O-Rings - Backup Rings