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3M Firestop Block B258, 12 PK, Maroon, 5.12 in W, 2 hr Fire Rating - Firestop Plugs & Blocks
3MFirestop Plugs & Blocks

3M Firestop Block B258, 12 PK, Maroon, 5.12 in W, 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

Also listed as: B 258 · B-258

Brand
3M
Item
Firestop Block B258, 12 PK, Maroon, 5.12 in W, 2 hr Fire Rating
Part Number
B258
Category
Firestop Plugs & Blocks
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Technical Specifications

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

Technical Documents

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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

What is the 3M Firestop Block used for?

The 3M Firestop Block (B258) is a passive fire protection device used to seal cable trays, conduit, and pipe penetrations in fire-rated walls and floors. It maintains the fire-resistance rating of the assembly, preventing the spread of flames and smoke during a fire.

What are the specifications of the 3M Firestop Block B258?

The 3M Firestop Block B258 is maroon, 8 inches long and 5.12 inches wide, with a 2-hour fire rating. It comes in a 12-pack. This 3M product is designed for use in fire-rated assemblies to seal penetrations and maintain compartmentation.

Where to buy 3M Firestop Blocks worldwide?

3G Electric supplies the 3M Firestop Block B258 to customers worldwide. We handle full logistics, customs clearance, and delivery to your site. Contact us for a quote and lead time on this 12-pack of firestop blocks.

How to install 3M Firestop Blocks?

Install 3M Firestop Blocks by placing them tightly around cables or pipes within the penetration opening. Ensure the block fully fills the gap and is flush with the wall surface. Follow the manufacturer's instructions for stacking and sealing multiple blocks to maintain the 2-hour fire rating.

Used in

Common applications for 3M
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Mining cable repair — 3M molded resin pouch for coating cable jackets in mine and portable cable applications.
Utility cable splicing — 3M cold shrink splice kit rated for 15 kV for insulating and repairing power cables.
Industrial wire harnessing — 3M 2520 series varnished cotton cloth tape for abrasion resistance in wire harnessing.
Structural bonding — 3M DP8005 acrylic adhesive for bonding plastics, metals, and composites in assembly operations.
Cable protection — 3M heat shrink tubing for sealing and protecting electrical connections from moisture and abrasion.
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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.

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Compatible alternatives & equivalents

Cross-referenced by specification & description
3M Firestop Pillow, model SLP-MEDIUM*, measures 9 in long by 6 in wide and is red in color. It provides a 3-hour fire rating and features an interlocking design for easy installation. Used to seal cable trays, conduit, and pipe penetrations in fire-rated walls and floors
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3M Firestop Pillow, model SLP-MEDIUM*, measures 9 in long by 6 in wide and is red in color. It provides a 3-hour fire rating and features an interlocking design for easy installation. Used to seal cable trays, conduit, and pipe penetrations in fire-rated walls and floors
This 3M firestop pillow is designed to seal openings in fire-rated walls and floors, helping to prevent the spread of flames and smoke. It measures 6 inches wide by 9 inches long, is red in color, and carries a 3-hour fire rating. The pillow is non-interlocking and is commonly used in cable trays, conduit penetrations, and temporary openings in commercial and industrial buildings
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This 3M firestop pillow is designed to seal openings in fire-rated walls and floors, helping to prevent the spread of flames and smoke. It measures 6 inches wide by 9 inches long, is red in color, and carries a 3-hour fire rating. The pillow is non-interlocking and is commonly used in cable trays, conduit penetrations, and temporary openings in commercial and industrial buildings
This firestop pillow is used to seal openings in fire-rated walls and floors, preventing the spread of flames and smoke. It is commonly applied in cable trays, conduit penetrations, and other through-penetrations in commercial and industrial buildings. The pillow measures 9 inches long by 4 inches wide, has a 3-hour fire rating, and is red in color
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This firestop pillow is used to seal openings in fire-rated walls and floors, preventing the spread of flames and smoke. It is commonly applied in cable trays, conduit penetrations, and other through-penetrations in commercial and industrial buildings. The pillow measures 9 inches long by 4 inches wide, has a 3-hour fire rating, and is red in color
Red, non-interlocking firestop pillow with a 3-hour fire rating. Measures 6 inches in width. Used for passive fire protection to seal openings around cables, pipes, and ducts in commercial and industrial buildings
3M
Red, non-interlocking firestop pillow with a 3-hour fire rating. Measures 6 inches in width. Used for passive fire protection to seal openings around cables, pipes, and ducts in commercial and industrial buildings
Round firestop passthrough for cables, rated for 4-hour fire protection. Overall length 12 inches, width 2 inches. Includes two mounting plates. Used to seal cable penetrations in fire-rated walls and floors in commercial and industrial facilities
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Round firestop passthrough for cables, rated for 4-hour fire protection. Overall length 12 inches, width 2 inches. Includes two mounting plates. Used to seal cable penetrations in fire-rated walls and floors in commercial and industrial facilities
This 3M firestop sheet is a silver panel designed to seal penetrations in fire-rated walls and floors, maintaining a 4-hour fire rating. It measures 28 inches in length and 1.33 feet in width. Suitable for use in passive fire protection systems in commercial and industrial construction
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This 3M firestop sheet is a silver panel designed to seal penetrations in fire-rated walls and floors, maintaining a 4-hour fire rating. It measures 28 inches in length and 1.33 feet in width. Suitable for use in passive fire protection systems in commercial and industrial construction

More from 3M

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This 4-pack of firestop plugs is used to seal openings in fire-rated walls and floors, maintaining the fire-resistance rating to limit the spread of flames and smoke. Each plug measures 5.2 in wide and has a 2-hour fire rating. Suitable for passive fire protection in commercial and industrial buildings
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This 4-pack of firestop plugs is used to seal openings in fire-rated walls and floors, maintaining the fire-resistance rating to limit the spread of flames and smoke. Each plug measures 5.2 in wide and has a 2-hour fire rating. Suitable for passive fire protection in commercial and industrial buildings
Maroon firestop plug with 2 in overall length and width, providing a 2-hour fire rating. Supplied in a pack of 4. Used for sealing openings around cables, pipes, or conduits in fire-rated walls and floors to prevent flame and smoke spread
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Maroon firestop plug with 2 in overall length and width, providing a 2-hour fire rating. Supplied in a pack of 4. Used for sealing openings around cables, pipes, or conduits in fire-rated walls and floors to prevent flame and smoke spread
The 3M Firestop Plank PK39 is a firestop plug designed to seal large openings in fire-rated walls and floors, preventing the spread of flames and smoke. Each plank measures 39 inches in length and 5.12 inches in width, with a maroon color and a 2-hour fire rating. This 3-pack is suitable for use in commercial and industrial construction where a 2-hour fire rating is required
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The 3M Firestop Plank PK39 is a firestop plug designed to seal large openings in fire-rated walls and floors, preventing the spread of flames and smoke. Each plank measures 39 inches in length and 5.12 inches in width, with a maroon color and a 2-hour fire rating. This 3-pack is suitable for use in commercial and industrial construction where a 2-hour fire rating is required

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