STIHL 3639 005 0081 26RS 20" Chain Loop
Product Number: 3639 005 0081
Stihl 3639-005-0081 OEM Chainsaw Chain (26RS • 20")
Genuine Stihl OEM Rapid Super (RS) full‑chisel chain designed for Farm Boss®, Wood Boss®, and professional mid‑range Stihl saws running a .325 pitch, .063 gauge setup. This is the factory‑correct 26RS chain loop — not aftermarket — sold by P&P Small Engines.
Product Overview
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Brand: Stihl (OEM)
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Stihl Part Number: 3639-005-0081
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Chain Model: 26RS (Rapid Super)
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Bar Length: 20 inch
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Pitch: .325" (8.25 mm)
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Gauge: .063" (1.6 mm)
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Drive Links: 81
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Cutter Type: Rapid Super (full chisel)
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Stock Number: 36390050081
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Condition: New OEM
This is the exact OEM chain specified by Stihl for saws equipped with a 20" .325 pitch .063 gauge guide bar.
Verify Fitment in 30 Seconds
Before ordering, confirm the following on your guide bar or current chain:
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Bar Length: 20"
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Pitch: .325"
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Gauge: .063"
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Drive Links: 81
⚠️ Full‑chisel RS chains are intended for experienced users and perform best in clean cutting conditions.
If you’re unsure about fitment, contact P&P Small Engines and we’ll help verify compatibility before you order.
Compatible Stihl Models
This OEM Stihl chain fits the following models when equipped with a 20" .325 pitch .063 gauge bar:
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MS 260 Pro
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MS 261
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MS 270
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MS 271 Farm Boss®
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MS 290 Farm Boss®
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MS 291 Farm Boss®
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MS 310
⚠️ Model alone does not guarantee fitment — bar specifications must match.
Product Specifications
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Brand: Stihl (OEM)
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OEM Part Number: 3639-005-0081
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Chain Model: 26RS Rapid Super
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Pitch: .325"
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Gauge: .063"
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Drive Links: 81
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Bar Length Compatibility: 20"
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Use Type: Firewood cutting, landowner use, professional cutting
Why Choose an OEM Stihl Rapid Super Chain?
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✅ Full‑chisel cutters for fast, aggressive cutting
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✅ Designed for higher‑torque Farm Boss® and pro saws
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✅ Excellent performance in clean wood
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✅ Manufactured to exact Stihl OEM specifications
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✅ Avoids fitment and safety issues common with aftermarket chains
OEM Stihl RS chains deliver maximum cutting speed and reliability.
Why Buy From P&P Small Engines?
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🔧 Knowledgeable Stihl parts specialists
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🔧 Genuine OEM Stihl products only
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🔧 Fitment support before purchase
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🔧 Fast, careful shipping
We help you get the right chain the first time.
Frequently Asked Questions
Q: Will this chain fit my MS 271 Farm Boss?
A: Yes, if your MS 271 is equipped with a 20" .325 pitch .063 gauge bar.
Q: Is this chain OEM Stihl?
A: Yes. This is a genuine Stihl OEM chain, part number 3639-005-0081.
Q: What does Rapid Super mean?
A: Rapid Super is Stihl’s full‑chisel cutter design, built for fast cutting in clean wood.
Common Search Terms
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Stihl 3639-005-0081 chain
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Stihl 26RS chain
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Stihl .325 .063 81DL chain
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Stihl MS 261 20 inch chain OEM
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Stihl Rapid Super chain
Questions?
If you need help confirming bar compatibility or selecting the correct chain, contact P&P Small Engines — we’re happy to help.




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