STIHL Chainsaw Chain 18" (45cm) 66 links RS 3/8" / 063" (1.6mm) - 3621 000 0066

Product Details & Features

The STIHL Chainsaw Chain – 18″ (45 cm), 66 Links, RS 3/8″ / .063″ (1.6 mm) – 3621 000 0066 is a genuine OEM saw chain engineered for high-performance cutting on compatible STIHL petrol and cordless chainsaws. This Rapid Super (RS) chain type is designed to deliver fast, smooth cutting with controlled vibration, excellent chip removal and long-lasting sharpness — making it well-suited for heavy-duty tasks such as felling, limbing, cutting firewood and general forestry work.

Built to STIHL’s exact original equipment specifications, the 3621 000 0066 chain features a 3/8″ pitch and .063″ (1.6 mm) gauge for robust cutting strength and durability. Its 66 drive links match 18″ (45 cm) guide bars that accept this pitch/gauge/length combination, ensuring correct engagement, reduced wear and reliable performance compared with many generic alternatives.

Key Features

• Genuine STIHL OEM Chain – Manufactured to original STIHL quality standards for accurate fitment and dependable performance.

• Rapid Super (RS) Design – Engineered profile for fast, smooth cutting with low vibration and improved control.

• 18″ (45 cm) Length – Ideal for medium-to-large cutting tasks on compatible saws.

• 3/8″ Pitch & .063″ (1.6 mm) Gauge – Standard professional-grade configuration for heavy woodcutting.

• 66 Drive Links – Correct link count for designated bar and sprocket assemblies.

• Part Reference: 3621 000 0066 – Confirms correct OEM STIHL chain identification.

Suitable Machines / Compatible Models

This 18″ RS saw chain is designed for use on STIHL chainsaws that accept an 18″ / 45 cm guide bar with a 3/8″ pitch, .063″ (1.6 mm) gauge and 66 drive links. Typical compatible models include:

• STIHL MS 260 / MS 260 C petrol chainsaws

• STIHL MS 261 / MS 261 C petrol chainsaws

• STIHL MS 270 / MS 270 C petrol chainsaws

• STIHL MS 271 / MS 271 C petrol chainsaws

• STIHL MS 280 / MS 280 C petrol chainsaws

• STIHL MS 290 / MS 290 C petrol chainsaws

• STIHL MS 291 / MS 291 C petrol chainsaws

• STIHL MS 310 / MS 310 C petrol chainsaws

• STIHL MS 340 petrol chainsaw

• STIHL MS 360 / MS 360 C petrol chainsaws

• STIHL MS 361 / MS 361 C petrol chainsaws

• STIHL MS 362 / MS 362 C petrol chainsaws

• STIHL MS 390 / MS 390 C petrol chainsaws

• STIHL MS 440 / MS 440 C petrol chainsaws

• STIHL MS 460 / MS 460 C petrol chainsaws

• STIHL MS 462 / MS 462 C petrol chainsaws

• STIHL MS 500i petrol chainsaw

• STIHL MS 651 / MS 660 / MS 661 heavy-duty petrol chainsaws

• Additional models where an 18″ RS 3/8″ chain is specified

(Exact fitment depends on production year and guide bar model — always verify with your machine’s parts diagram before ordering.)

Typical Compatible Applications

This RS chain is commonly used for:

• Felling medium to large trees

• Limb removal and crown reduction

• Bucking firewood and seasoned timber

• Forestry, landscaping and grounds maintenance

• Heavy-duty woodcutting where rapid, smooth cuts are required

Parts This Chain Replaces / Supersedes

The 3621 000 0066 chain is the direct OEM replacement for the original RS saw chain specified for its applications. Alternate references you may see include:

• 3621-003-0066 — Alternate OEM listing format

• 36210030066 / 36210000066 — Catalogue variants

(Always validate the reference number against your parts diagram.)

Fitment Tip

Chainsaw chains must match the correct guide bar length, pitch, gauge and number of drive links to ensure safe, efficient cutting. Before ordering, measure your existing chain’s drive link count, confirm your guide bar’s specifications and consult the official STIHL parts manual to confirm that 3621 000 0066 is correct for your machine. Proper fitment ensures smoother operation, longer chain and bar life and reduced wear.

Product Details

Product Type: Chainsaw Chain – Rapid Super (RS)
Part Reference: 3621 000 0066
Bar Length: 18″ / 45 cm
Pitch: 3/8″ (9.53 mm)
Gauge: .063″ (1.6 mm)
Drive Links: 66
Function: Provides high-performance cutting for compatible STIHL chainsaws

Why Choose This Chainsaw Chain

The STIHL 3621 000 0066 18″ RS Chain is the dependable OEM choice when replacing a dull, damaged or worn chain on compatible STIHL machines. Its durable construction and rapid-cutting design deliver smoother cuts, reduced vibration and long-lasting performance compared with many generic alternatives — helping you maintain efficient cutting, lower fatigue and maximise uptime in demanding woodcutting tasks.