IDEAL GUIDE BAR [20"] [0.325"] CHAINSAW SPARE PART - 27939
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The IDEAL 20" Chainsaw Guide Bar (Part No. 27939) is a professional-grade replacement bar engineered for demanding forestry and timber work. Built from laminated high-tensile alloy steel with induction-hardened wear rails and a precision sprocket nose, this 0.325" pitch guide bar delivers straight, controlled cuts with minimal friction and extended service life, a reliable chainsaw spare part for both professionals and serious DIYers.
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Professional Cutting Precision — Built to Last in the Field
- 500mm (20") Cutting Reach — Delivers the wide reach and deep cutting capacity required for felling medium-to-large trees, processing large-diameter logs, and tackling demanding forestry applications where shorter bars fall short.
- 0.325" Pitch Sprocket Nose with Low-Friction Bearing — The precision-engineered nose sprocket rotates smoothly around the bar tip, actively reducing chain friction, heat buildup, and power loss during sustained high-load cutting — extending both bar and chain service intervals.
- Induction-Hardened Wear Rails — The running rails undergo a specialist heat-treatment process that dramatically increases surface hardness, resisting the grooving, scoring, and premature wear caused by high-speed chain contact under heavy cutting loads.
- Laminated High-Tensile Alloy Steel Body — Constructed from electrically welded, multi-plate high-tensile steel, the bar body achieves an optimal balance of structural rigidity, vibration damping, and reduced operational fatigue — critical for extended professional use.
- Integrated Automatic Lubrication System — Precision-drilled oil feeder holes and machined rail channels continuously distribute chain oil across the full groove length during operation, ensuring consistent lubrication without manual intervention and significantly extending bar and chain longevity.
- Universal Commercial-Grade Fit — Engineered as a direct-fit replacement spare part for standard gas-powered and cordless chainsaws using 0.325" pitch drive sprockets with a 1.5mm (0.058") chain gauge and 76 drive links — compatible with a wide range of professional chainsaw brands and models.
This guide bar is manufactured to commercial-grade quality standards, meeting the performance and dimensional tolerances expected of professional chainsaw replacement parts. The package includes one 20" Guide Bar (Part No. 27939), ready for direct installation on compatible chainsaw models.
General Purchase & Comparison Queries
Is this guide bar a genuine OEM part or an aftermarket replacement?
The IDEAL 27939 Guide Bar is a professional aftermarket replacement part manufactured to commercial-grade dimensional and performance tolerances. It is engineered as a direct-fit replacement for chainsaws using a 0.325" pitch, 1.5mm gauge chain, and 76 drive links — offering equivalent or superior durability to many OEM bars thanks to its induction-hardened rails and laminated high-tensile alloy steel body.
How does this bar compare to a standard solid-nose bar?
Unlike a solid-nose bar, the IDEAL 27939 features a sprocket nose with a low-friction bearing. This rotating nose sprocket significantly reduces friction and heat at the bar tip, resulting in less power loss, lower chain wear, and longer bar life — particularly beneficial during sustained heavy-duty cutting such as felling or bucking large-diameter timber. Solid-nose bars are generally reserved for very light-duty or occasional use.
What should I check before purchasing to confirm compatibility with my chainsaw?
Before ordering, confirm three key specifications on your existing bar or chainsaw manual: (1) Bar length — 20" / 500mm, (2) Chain pitch — 0.325", and (3) Chain gauge — 1.5mm (0.058"). Additionally, verify your chainsaw's drive sprocket pitch matches 0.325" and that the bar mount slot dimensions are compatible. The drive link count of 76 links should also match your replacement chain if purchasing both together.
Product-Specific and Usage Queries
How does the automatic lubrication system work on this guide bar?
The IDEAL 27939 features an integrated automatic lubrication system comprising a precision-drilled oil feeder hole and machined rail channels. During operation, the chainsaw's oil pump feeds bar-and-chain oil through the feeder hole, which is then distributed continuously along the full length of the rail groove. This ensures the chain receives consistent lubrication at all times without manual intervention, reducing friction, heat, and wear on both the bar rails and chain drive links.
What types of cutting tasks is a 20" bar best suited for?
A 20" (500mm) guide bar is ideally suited for medium-to-large scale forestry and timber work, including felling trees with trunk diameters up to approximately 35–40cm, bucking and cross-cutting large logs, clearing storm-damaged timber, and general land-clearing operations. It provides the reach and cutting depth that shorter bars cannot achieve, while remaining manageable for experienced operators. It is less suited for light pruning or confined-space work where a shorter bar would be more practical.
Does this bar require any break-in procedure before heavy use?
Yes — as with all new guide bars, a short break-in period is recommended. For the first 30–60 minutes of use, run the chainsaw at moderate load rather than full throttle, and check chain tension frequently as new chains and bars seat together. Ensure the oil reservoir is full and the automatic oiling system is functioning correctly before starting. After the break-in period, re-tension the chain, inspect the bar rails for even wear, and resume normal operation. This process extends the service life of both the bar and chain significantly.
Problem/Solution-Oriented Queries
My chainsaw bar is wearing unevenly on one side — will this replacement bar fix the issue?
Uneven rail wear is typically caused by incorrect chain tension, insufficient lubrication, or a worn drive sprocket — not the bar itself. Replacing the bar with the IDEAL 27939 will provide fresh induction-hardened rails, but the underlying cause must be addressed first. Check that your oil feeder hole is unobstructed, the chain is tensioned correctly, and the drive sprocket shows no hooked or uneven wear. Replacing the sprocket at the same time as the bar and chain is strongly recommended to prevent premature wear on the new components.
The chain keeps coming off the bar during use — could the bar be the problem?
Chain derailment is most commonly caused by incorrect chain tension, a worn or damaged bar groove, or a mismatched chain gauge. If your existing bar's groove has widened due to wear, the chain drive links will no longer seat securely — making replacement necessary. The IDEAL 27939 features a 1.5mm (0.058") gauge groove; ensure your replacement chain matches this gauge exactly. After fitting, set chain tension correctly — the chain should snap back when pulled slightly away from the bar — and re-check tension after the first few minutes of operation as new components bed in.
The bar is overheating during use — what could be causing this and how can I prevent it?
Bar overheating is almost always a lubrication failure. First, confirm the oil reservoir is filled with the correct bar-and-chain oil and that the automatic oiling system is delivering oil to the bar (hold the running saw over a light surface — you should see an oil mist). If the oil feeder hole or rail channel is blocked, clean it with a thin wire or compressed air. Overheating can also result from excessive chain tension or a dull chain forcing the operator to apply excessive pressure. The IDEAL 27939's integrated lubrication channels are designed to maintain consistent oil flow — keeping them clean is the single most effective preventive measure.