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90A Durometer Urethane Back-Up Rings -350 Dash Size, Per Pack

Description & Features

These Hercules Sealing Products 90A Durometer Urethane Back-Up Rings -350 Dash Size, are molded of 90A durometer urethane for excellent extrusion resistance. These back-up rings correspond to standard O-Ring sizes. The urethane material provides a temperature range of -65°F to 220°F.

This is a per-pack item, with a quantity of three back-up rings included in each pack. These 90A Durometer Urethane Back-Up Rings are stretched for easy installation, and quickly return to their original size.

SKU: 575-350

Supplier Part Number (MPN): 575-350

Alternate Part Numbers: C1BV59, MI-01263740, MINO-00407X80416

Specifications

Alternate Part Numbers Alternate Part Number C1BV59, Alternate Part Number MI-01263740, Alternate Part Number MINO-00407X80416	Dash Size -350	Brand Hercules Sealing Products	Brand Hercules Sealing Products	Pack Size 1.00	UOM EA	Package Qty. 3	Supplier Part Number 575-350	Type Urethane	Product Weight 0.01 lbs

Similar Products

Model Number	Dash Size	Type	Package Qty.
575-014 90A Urethane Back-Up Ring	-014	Urethane	10
575-038 90A Urethane Back-Up Ring	-038	Urethane	10
575-212 90A Urethane Back-Up Ring	-212	Urethane	9
575-214 90A Urethane Back-Up Ring	-214	Urethane	9
575-217 90A Urethane Back-Up Ring	-217	Urethane	9
575-228 90A Urethane Back-Up Ring	-228	Urethane	10
575-231 90A Urethane Back-Up Ring	-231	Urethane	7
575-232 90A Urethane Back-Up Ring	-232	Urethane	7
575-236 90A Urethane Back-Up Ring	-236	Urethane	6
575-244 90A Urethane Back-Up Ring	-244	Urethane	4
575-252 90A Urethane Back-Up Ring	-252	Urethane	3
575-256 90A Urethane Back-Up Ring	-256	Urethane	2
575-329 90A Urethane Back-Up Ring	-329	Urethane	8
575-334 90A Urethane Back-Up Ring	-334	Urethane	7
575-338 90A Urethane Back-Up Ring	-338	Urethane	7
575-342 90A Urethane Back-Up Ring	-342	Urethane	5
575-346 90A Urethane Back-Up Ring	-346	Urethane	4
575-358 90A Urethane Back-Up Ring	-358	Urethane	2
575-011 90A Urethane Back-Up Ring	-011	Urethane	10
575-012 90A Urethane Back-Up Ring	-012	Urethane	10
575-015 90A Urethane Back-Up Ring	-015	Urethane	10
575-016 90A Urethane Back-Up Ring	-016	Urethane	10
575-017 90A Urethane Back-Up Ring	-017	Urethane	10
575-018 90A Urethane Back-Up Ring	-018	Urethane	10
575-020 90A Urethane Back-Up Ring	-020	Urethane	10
575-021 90A Urethane Back-Up Ring	-021	Urethane	10
575-022 90A Urethane Back-Up Ring	-022	Urethane	10
575-029 90A Urethane Back-Up Ring	-029	Urethane	10
575-030 90A Urethane Back-Up Ring	-030	Urethane	10
575-110 90A Urethane Back-Up Ring	-110	Urethane	9
575-111 90A Urethane Back-Up Ring	-111	Urethane	9
575-112 90A Urethane Back-Up Ring	-112	Urethane	9
575-113 90A Urethane Back-Up Ring	-113	Urethane	9
575-114 90A Urethane Back-Up Ring	-114	Urethane	9
575-115 90A Urethane Back-Up Ring	-115	Urethane	9
575-116 90A Urethane Back-Up Ring	-116	Urethane	9
575-117 90A Urethane Back-Up Ring	-117	Urethane	9
575-118 90A Urethane Back-Up Ring	-118	Urethane	9
575-119 90A Urethane Back-Up Ring	-119	Urethane	9
575-120 90A Urethane Back-Up Ring	-120	Urethane	8
575-121 90A Urethane Back-Up Ring	-121	Urethane	8
575-122 90A Urethane Back-Up Ring	-122	Urethane	8
575-124 90A Urethane Back-Up Ring	-124	Urethane	8
575-125 90A Urethane Back-Up Ring	-125	Urethane	8
575-126 90A Urethane Back-Up Ring	-126	Urethane	8
575-127 90A Urethane Back-Up Ring	-127	Urethane	8
575-128 90A Urethane Back-Up Ring	-128	Urethane	8
575-129 90A Urethane Back-Up Ring	-129	Urethane	8
575-132 90A Urethane Back-Up Ring	-132	Urethane	8
575-133 90A Urethane Back-Up Ring	-133	Urethane	8
575-135 90A Urethane Back-Up Ring	-135	Urethane	8
575-136 90A Urethane Back-Up Ring	-136	Urethane	8
575-137 90A Urethane Back-Up Ring	-137	Urethane	8
575-140 90A Urethane Back-Up Ring	-140	Urethane	10
575-141 90A Urethane Back-Up Ring	-141	Urethane	7
575-145 90A Urethane Back-Up Ring	-145	Urethane	6
575-149 90A Urethane Back-Up Ring	-149	Urethane	6
575-151 90A Urethane Back-Up Ring	-151	Urethane	6
575-154 90A Urethane Back-Up Ring	-154	Urethane	3
575-155 90A Urethane Back-Up Ring	-155	Urethane	3
575-157 90A Urethane Back-Up Ring	-157	Urethane	3
575-208 90A Urethane Back-Up Ring	-208	Urethane	10
575-209 90A Urethane Back-Up Ring	-209	Urethane	9
575-210 90A Urethane Back-Up Ring	-210	Urethane	9
575-211 90A Urethane Back-Up Ring	-211	Urethane	9
575-213 90A Urethane Back-Up Ring	-213	Urethane	9
575-215 90A Urethane Back-Up Ring	-215	Urethane	9
575-216 90A Urethane Back-Up Ring	-216	Urethane	9
575-218 90A Urethane Back-Up Ring	-218	Urethane	9
575-219 90A Urethane Back-Up Ring	-219	Urethane	9
575-220 90A Urethane Back-Up Ring	-220	Urethane	10
575-221 90A Urethane Back-Up Ring	-221	Urethane	10
575-222 90A Urethane Back-Up Ring	-222	Urethane	10
575-223 90A Urethane Back-Up Ring	-223	Urethane	8
575-224 90A Urethane Back-Up Ring	-224	Urethane	8
575-225 90A Urethane Back-Up Ring	-225	Urethane	10
575-226 90A Urethane Back-Up Ring	-226	Urethane	10
575-227 90A Urethane Back-Up Ring	-227	Urethane	10
575-229 90A Urethane Back-Up Ring	-229	Urethane	10
575-230 90A Urethane Back-Up Ring	-230	Urethane	7
575-233 90A Urethane Back-Up Ring	-233	Urethane	7
575-234 90A Urethane Back-Up Ring	-234	Urethane	6
575-235 90A Urethane Back-Up Ring	-235	Urethane	6
575-237 90A Urethane Back-Up Ring	-237	Urethane	5
575-238 90A Urethane Back-Up Ring	-238	Urethane	5
575-239 90A Urethane Back-Up Ring	-239	Urethane	5
575-240 90A Urethane Back-Up Ring	-240	Urethane	5
575-241 90A Urethane Back-Up Ring	-241	Urethane	5
575-242 90A Urethane Back-Up Ring	-242	Urethane	5
575-243 90A Urethane Back-Up Ring	-243	Urethane	5
575-245 90A Urethane Back-Up Ring	-245	Urethane	4
575-246 90A Urethane Back-Up Ring	-246	Urethane	3
575-247 90A Urethane Back-Up Ring	-247	Urethane	3
575-248 90A Urethane Back-Up Ring	-248	Urethane	3
575-249 90A Urethane Back-Up Ring	-249	Urethane	3
575-253 90A Urethane Back-Up Ring	-253	Urethane	3
575-254 90A Urethane Back-Up Ring	-254	Urethane	3
575-255 90A Urethane Back-Up Ring	-255	Urethane	2
575-258 90A Urethane Back-Up Ring	-258	Urethane	2
575-259 90A Urethane Back-Up Ring	-259	Urethane	2
575-260 90A Urethane Back-Up Ring	-260	Urethane	2
575-261 90A Urethane Back-Up Ring	-261	Urethane	2
575-262 90A Urethane Back-Up Ring	-262	Urethane	2
575-314 90A Urethane Back-Up Ring	-314	Urethane	8
575-316 90A Urethane Back-Up Ring	-316	Urethane	8
575-321 90A Urethane Back-Up Ring	-321	Urethane	8
575-324 90A Urethane Back-Up Ring	-324	Urethane	8
575-325 90A Urethane Back-Up Ring	-325	Urethane	8
575-326 90A Urethane Back-Up Ring	-326	Urethane	8
575-327 90A Urethane Back-Up Ring	-327	Urethane	8
575-328 90A Urethane Back-Up Ring	-328	Urethane	8
575-330 90A Urethane Back-Up Ring	-330	Urethane	8
575-331 90A Urethane Back-Up Ring	-331	Urethane	8
575-332 90A Urethane Back-Up Ring	-332	Urethane	8
575-333 90A Urethane Back-Up Ring	-333	Urethane	8
575-335 90A Urethane Back-Up Ring	-335	Urethane	7
575-336 90A Urethane Back-Up Ring	-336	Urethane	7
575-337 90A Urethane Back-Up Ring	-337	Urethane	7
575-339 90A Urethane Back-Up Ring	-339	Urethane	6
575-340 90A Urethane Back-Up Ring	-340	Urethane	6
575-341 90A Urethane Back-Up Ring	-341	Urethane	6
575-344 90A Urethane Back-Up Ring	-344	Urethane	4
575-345 90A Urethane Back-Up Ring	-345	Urethane	4
575-347 90A Urethane Back-Up Ring	-347	Urethane	4
575-348 90A Urethane Back-Up Ring	-348	Urethane	4
575-349 90A Urethane Back-Up Ring	-349	Urethane	3
575-350 90A Urethane Back-Up Ring	-350	Urethane	3
575-425 90A Urethane Back-Up Ring	-425	Urethane	3
575-427 90A Urethane Back-Up Ring	-427	Urethane	3
575-429 90A Urethane Back-Up Ring	-429	Urethane	3
575-432 90A Urethane Back-Up Ring	-432	Urethane	2
575-433 90A Urethane Back-Up Ring	-433	Urethane	2
575-434 90A Urethane Back-Up Ring	-434	Urethane	2
575-436 90A Urethane Back-Up Ring	-436	Urethane	2
575-439 90A Urethane Back-Up Ring	-439	Urethane	2

Product Questions & Answers (1)

Question by: Randy M on Feb 8, 2026, 6:36 AM

these stretch for install and snap back to size -- how hard is it actually to get a -350 size seated without it rolling or bunching up?

Answer by: Customer Support on Feb 9, 2026, 6:15 PM

Urethane has enough flex to stretch over the groove edge without needing special tools in most cases. The 90A durometer keeps it firm enough that it snaps back into shape pretty reliably once it clears the lip. For a -350 dash size you're working with a larger ring, so taking your time and working it around evenly rather than pulling from one spot makes the difference between a clean seat and a twisted mess. The material memory does most of the work for you once it's positioned.