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172 PTFE SOLID BACKUP RING FDA

PTFE Back-Up Ring, 8.237 in ID x 0.103 CS, 55D, White, -65 to 500°F

Status
Out of Stock
Est. Ship Date
21 Oct 2026
Material
PTFE (Polytetrafluoroethylene)
Dash Size
172
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
3/32 inch
Nominal Inside Diameter
8 1/4 inch
Nominal Outside Diameter
8 7/16 inch
Unit of Measure
EA
SKU:
TST172SO

Product Specification

-
Ordered as TST172SO, this is an AS568-172 white PTFE (Teflon) 55 Shore D Back-Up Ring measuring an inside diameter of 8.237 in (209.22 mm), a cross section of 0.103 in (2.62 mm), and an outside diameter of 8.443 in (214.45 mm). The back-up ring extends o-ring service life by supporting the seal against extrusion under high pressure.

As a material, PTFE (Teflon) is specified for excellent dielectric properties and a very wide continuous service temperature range. Expect good resistance to nearly all industrial chemicals, oxidizing media, and strong acids and bases. Service temperature is rated from -65°F (-53.9°C) through 500°F (260°C). Exposure to elemental fluorine at temperature or molten alkali metals will shorten service life.

You will find this material specified across laboratory equipment, food and beverage, and pharmaceutical and biotech.

Order part number TST172SO, sold individually. Nominal inside diameter is listed as 8 1/4 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
TST172SO
Description
172 PTFE SOLID BACKUP RING FDA
Actual Cross Section
0.103 inch (2.62 mm)
Actual Inside Diameter
8.237 inch (209.22 mm)
Actual Outside Diameter
8.443 inch (214.45 mm)
FDA Compliant
No
Measurement System
Imperial
Metal Detectable
No
NSF Certified
No
Product Code
6002
Product Category
O-Rings - Backup Rings