What is Loctite SI 5900 designed for?

This black silicone sealant is designed for flexible flange sealing and stamped sheet metal covers like oil pans, timing covers, and valve covers.

Which materials does this sealant adhere to?

The thixotropic paste provides excellent adhesion to metal, plastic, glass, and ceramic substrates.

What is the operating temperature range?

The product withstands service operating temperatures ranging from -55 °C to +200 °C.

What is the skin-over time of this sealant?

At room temperature, the sealant achieves a tack-free skin-over time of 15 minutes.

LOCTITE 5900 sealant black (300 ml) - 2061875

Name: LOCTITE 5900 sealant black (300 ml) - 2061875
Brand: LOCTITE
SKU: 11010436
Price: 57.4 EUR
Availability: InStock

Supplier number: LOCTITE 2061875 | EAN 5010266235844

From 1 piece €57.40

From 12 pieces €54.53 - €34.44 saving

From 24 pieces €53.09 - €103.32 saving

From 36 pieces €51.66 - €206.64 saving

57.40 tax incl.

€47.44 excl. VAT (incl. all environmental contributions)

On stock - immediately available

Ordered before 20:00 - delivered as of 05/10/2026
Shipping costs €11.99 VAT included | Free shipping for orders over a total amount of 125 euros
Delivery by DHL

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How does it work?

For a purchase value of €99 to €125 excl. VAT, receive FREE LOCTITE 55 thread sealing cord 50 m (IDH 528244) worth €9.99.
For a purchase value of more than €125 excl. VAT, receive FREE LOCTITE SF 7850 hand cleaner 400 ml (IDH 2098250) worth €13.21.
The free item is automatically added to your order. No registration is required.
The promotion is valid from 01.10.2026 to 31.10.2026.
Loctite Buy & Get deals are recognisable by the promotion label on the product page. Click the label to view all available deals.

Reliable flange sealing with Loctite

Practical benefits

Superior resistance to oil: You create a durable, flexible seal that withstands engine oil, transmission fluids, and continuous joint movement.
High gap filling capability: You reliably fill gaps up to 6.35 mm across metal, plastic, glass, and ceramic surfaces without cracking or shrinking.
Fast skinning for assembly: With a skin-over time of 15 minutes, you speed up processing and can perform early low-pressure testing.

In a nutshell

The right choise for

With Loctite si 5900 bk Ultra Black silicone sealant, you create reliable, flexible flange seals on oil pans, valve covers, and timing covers. This thixotropic black paste does not sag during vertical application and adheres strongly to metal, plastic, glass, and ceramic surfaces. You can reliably bridge gaps up to 6.35 mm without shrinking or cracking, eliminating the need for pre-cut solid gaskets. The flexible bond resists automotive engine oils, transmission fluids, and coolants while absorbing vibrations across temperatures from -55 °C to +200 °C. Featuring a fast 15-minute skin-over time and early low-pressure test capability, this 300 ml cartridge helps you complete engine overhauls quickly and efficiently.

Product information FAQ

€57.40

In stock - tax incl.

Key features according to our expert

Net volume: 300 ml
Relative density: 1,31
ADR packing group: Not applicable
ADR class: Not applicable
Packaging: Cartridge
Principal hazard property: GHS05 Corrosive
UN number: Not applicable
P-statements: P201; P280; P305 + P351 + P338; P308 + P311; P333 + P313
H-statements: H317; H318; H350; H371
Hazard class: GHS05 Corrosive; GHS07 Harmful or irritant; GHS08 Health hazard
Physical state: Solid
Fire resistant: No

Product description:

LOCTITE SI 5900 is a low strength, moisture-curing, silicone-based thixotropic paste.
Typical applications include stamped sheet metal covers (timing covers and oil sumps).
It exhibits a rapid skin-over time of 15 minutes and is suitable for gaps up to 1 mm.
As a single component it requires no mixing.

Precautionary statements

P201: Obtain special instructions before use.
P280: Wear protective gloves/protective clothing/eye protection/face protection.
P305 + P351 + P338: IF IN EYES: Rinse cautiously with water for several minutes. Remove contact lenses, if present and easy to do. Continue rinsing.
P333 + P313: If skin irritation or rash occurs: Get medical advice/attention.

Hazard statements

H317: May cause an allergic skin reaction.
H318: Causes serious eye damage.
H350: May cause cancer.
H371: May cause damage to organs.

All Features

Net volume: 300 ml
Relative density: 1,31
Adr packing group: Not applicable
Adr class: Not applicable
Packaging: Cartridge
Principal hazard property: GHS05 Corrosive
Un number: Not applicable
P-statements: P201; P280; P305 + P351 + P338; P308 + P311; P333 + P313
H-statements: H317; H318; H350; H371
Hazard class: GHS05 Corrosive; GHS07 Harmful or irritant; GHS08 Health hazard
Physical state: Solid
Fire resistant: No

Brand LOCTITE
11010436
EAN 5010266235844
Supplier number LOCTITE 2061875

Frequently asked questions about this product

Answered by specialists

What is Loctite SI 5900 designed for?: This black silicone sealant is designed for flexible flange sealing and stamped sheet metal covers like oil pans, timing covers, and valve covers.
Which materials does this sealant adhere to?: The thixotropic paste provides excellent adhesion to metal, plastic, glass, and ceramic substrates.
How resistant is it to engine oils and fluids?: It offers outstanding resistance to automotive engine oils, transmission fluids, and coolants while accommodating joint movement.
What is the operating temperature range?: The product withstands service operating temperatures ranging from -55 °C to +200 °C.
What is the skin-over time of this sealant?: At room temperature, the sealant achieves a tack-free skin-over time of 15 minutes.