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STIHL MS 391 Chain: Size Chart & Replacement Chain Loops

Posted by Outdoor Power LLC Parts Team on

Quick answer: pick your bar length below and add the matching STIHL chain loop to your cart. Every loop is genuine STIHL chain cut from the reel and ships nationwide (free shipping on orders $125+).

STIHL MS 391 chain size chart

Bar Chain loop Pitch / gauge / drive links Price
16" (.050" bar) STIHL 33RS60
Rapid Super 3 – full chisel 		3/8" / .050" / 60 DL $37.20
18" (.050" bar) STIHL 33RS66
Rapid Super 3 – full chisel 		3/8" / .050" / 66 DL $40.92
20" (.050" bar) STIHL 33RS72
Rapid Super 3 – full chisel 		3/8" / .050" / 72 DL $44.64
16" (.063" bar) STIHL 36RS60
Rapid Super 3 – full chisel 		3/8" / .063" / 60 DL $39.00
16" (.063" bar) STIHL 36RM60
Rapid Micro 3 – semi-chisel 		3/8" / .063" / 60 DL $31.20
18" (.063" bar) STIHL 36RS66
Rapid Super 3 – full chisel 		3/8" / .063" / 66 DL $42.90
18" (.063" bar) STIHL 36RM66
Rapid Micro 3 – semi-chisel 		3/8" / .063" / 66 DL $34.32
Not sure which bar you have? Check the numbers stamped on the bar tail: pitch, gauge and drive-link count. The same "16-inch" bar can take a different chain depending on the bar mount, so the drive-link count is what matters.

Chain types for the MS 391

  • Rapid Super 3 (33RS): 3/8" pitch, .050" gauge, full chisel; sharpen with a 13/64" (5.2 mm) round file.
  • Rapid Super 3 (36RS): 3/8" pitch, .063" gauge, full chisel; sharpen with a 13/64" (5.2 mm) round file.
  • Rapid Micro 3 (36RM): 3/8" pitch, .063" gauge, semi-chisel; sharpen with a 13/64" (5.2 mm) round file.

Which chain should I buy?

For general firewood and storm cleanup, the semi-chisel loops (RM / PM) are the safest choice: they forgive dirt and are quick to touch up with a file. If you cut clean, seasoned wood and want maximum speed, choose the full-chisel loops (RS / PS). Buying two loops and rotating them is the easiest way to keep the saw cutting while one is being sharpened.

MS 391 chain FAQ

What size chain does a STIHL MS 391 take?

The STIHL MS 391 runs 3/8" pitch chain. The loop depends on your bar length and gauge: 16" (.050" bar) bar = 33RS60; 18" (.050" bar) bar = 33RS66; 20" (.050" bar) bar = 33RS72; 16" (.063" bar) bar = 36RS60/36RM60; 18" (.063" bar) bar = 36RS66/36RM66. Match the drive-link count stamped on your bar.

How do I count drive links?

Lay the chain flat and count the tangs on the inside of the loop, the parts that ride in the bar groove. That number must match exactly; one off and the chain will not tension correctly.

Semi-chisel or full chisel?

Full chisel (RS/PS) cuts fastest in clean wood. Semi-chisel (RM/PM) stays sharp longer in dirty, frozen or storm-damaged wood and is easier to sharpen.

More: STIHL chain by saw model (all saws) · STIHL chain cross reference · STIHL parts · STIHL chainsaw won't start

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