Send a part number, a photo, or a whole BOM — we supply it and stand behind it. Worldwide shipping to 80+ countries.

3G Electric
RFQ CartGet a QuoteSign inSign up
3M Firestop Block: 8 in Overall Lg, 5.12 in Overall Wd, 2 hr Fire Rating - Firestop Plugs & Blocks
3MFirestop Plugs & Blocks

3M Firestop Block: 8 in Overall Lg, 5.12 in Overall Wd, 2 hr Fire Rating

The 3M Firestop Block (MPN B258) is a maroon firestop plug and block, 8 inches long and 5.12 inches wide, with a 2-hour fire rating, sold in a 12-pack. This 3M product provides a passive fire protection solution for…

SKU 3G-OTH-552164

Brand
3M
Item
Firestop Block: 8 in Overall Lg, 5.12 in Overall Wd, 2 hr Fire Rating
Category
Firestop Plugs & Blocks
Available to Order
Trade pricing by quote — replies within 24h
Qty
WhatsApp an engineer
No account needed — your quote request goes straight to our engineers. A free account lets you track quotes and re-order faster.
Worldwide Shipping
Air & sea freight
Datasheet on Request
Technical specs
1-Day Quote
Replies within 24h

Technical Specifications

3M
Manufacturer Part Number
B258
Type
12 PK
Color
Maroon
Overall Wd
5.12 in
Fire Rating
2 hr
View Full Spec Sheet

Technical Documents

No technical documents available for this product.
Request documentation →
Not sure this is the right part? Get a recommendation.

Need installation or engineering help?

Installation, commissioning, maintenance plans, system design, and bundled product + service quotes — one team handles the full scope.
Talk to an engineer

Ask a question

3M Products
3G Electric (S) Pte. Ltd. — Singapore

Product Description

The 3M Firestop Block (MPN B258) is a maroon firestop plug and block, 8 inches long and 5.12 inches wide, with a 2-hour fire rating, sold in a 12-pack. This 3M product provides a passive fire protection solution for sealing penetrations in fire-rated assemblies.

Frequently Asked Questions

Is the 3M Firestop Block: 8 in Overall Lg, 5.12 in Overall Wd, 2 hr Fire Rating available from 3G Electric?

Yes — 3G Electric supplies genuine 3M products, available to order with worldwide shipping. Contact us for current lead time.

How do I get a quote for the 3M Firestop Block: 8 in Overall Lg, 5.12 in Overall Wd, 2 hr Fire Rating?

Click "Request a Quote" on this page or add the product to your RFQ cart. Our engineers will respond within 24 hours with pricing, lead times, and technical recommendations.

Does 3G Electric provide technical support for firestop plugs & blocks?

Yes, our team of experienced engineers provides full technical support including product selection, installation guidance, commissioning, and after-sales service for all firestop plugs & blocks we distribute.

Used in

Common applications for 3M
Industrial process water filtration — 3M solid polypropylene cartridge (e.g., RT10Q16G20NN, 7 micron) for sediment removal in manufacturing lines.
Cooling tower pre-treatment — 3M string-wound cartridge (e.g., RT39B16G20NN, 30 micron) to protect heat exchangers from particulate fouling.
Food and beverage rinse water — 3M 1 micron solid cartridge (RT10Y16G20NN) for fine filtration to meet quality standards.
Chemical processing feed water — 3M 27 micron solid cartridge (RT30L16G20NN) for high-flow sediment reduction upstream of sensitive equipment.
Wastewater effluent polishing — 3M 2 micron string-wound cartridge (RT09Y16G20NN) for final particulate removal before discharge or reuse.
Pharmaceutical utility water — 3M 0 micron string-wound cartridge (RT09L16G20NN) for sub-micron filtration in critical systems.

3M Products

3G Electric supplies 3M firestop plugs & blocks. We supply genuine products with in-stock availability on common SKUs, technical documentation, commissioning support, and warranty service — worldwide.

You might also need

Burners & Combustion →Pumps & Compressors →Spare Parts →All Products →

More from 3M

View all 3M parts →
3M Firestop Plank: 39 in Overall Lg, 5.12 in Overall Wd, 2 hr Fire Rating, 3 PK (MPN PK39). Key specifications — Color: Maroon; Fire Rating: 2 hr; Brand: 3M.
3M
3M Firestop Plank: 39 in Overall Lg, 5.12 in Overall Wd, 2 hr Fire Rating, 3 PK (MPN PK39). Key specifications — Color: Maroon; Fire Rating: 2 hr; Brand: 3M.
3M Firestop Plug: 4 in Overall Lg, 5.2 in Overall Wd, 2 hr Fire Rating, 4 PK (MPN PLG4). Key specifications — Color: White; Fire Rating: 2 hr; Brand: 3M.
3M
3M Firestop Plug: 4 in Overall Lg, 5.2 in Overall Wd, 2 hr Fire Rating, 4 PK (MPN PLG4). Key specifications — Color: White; Fire Rating: 2 hr; Brand: 3M.
3M Firestop Plug: 2 in Overall Lg, 2 in Overall Wd, 2 hr Fire Rating, 4 PK (MPN PLG2). Key specifications — Color: Maroon; Fire Rating: 2 hr; Brand: 3M.
3M
3M Firestop Plug: 2 in Overall Lg, 2 in Overall Wd, 2 hr Fire Rating, 4 PK (MPN PLG2). Key specifications — Color: Maroon; Fire Rating: 2 hr; Brand: 3M.