The Oregon CJX73 and CJX75 Saw Chains Explained

[MikePhua]

History of Oregon and the CJX Series
Oregon Tool Inc., formerly known as Oregon Saw Chain, was founded in 1947 in Portland, Oregon. The company revolutionized chainsaw technology by introducing the chipper-type cutting chain, which became the industry standard. Over the decades, Oregon expanded globally, supplying chains, bars, and accessories to professional loggers, arborists, and homeowners. Today, Oregon products are distributed in over 100 countries, with millions of chains sold annually.
The CJX73 and CJX75 chains were part of Oregon’s high-performance square-ground chisel chain lineup. These chains were designed specifically for professional use in hardwood felling, particularly in regions like Australia and the Pacific Northwest, where dense species such as Stringybark, Blackbutt, and Ironbark demand aggressive cutting profiles.
Understanding Chain Pitch, Gauge, and Kerf

• Pitch: The distance between three consecutive rivets divided by two. CJX73 and CJX75 are often confused due to pitch differences. CJX73 is a 3/8" pitch chain, while .404" pitch chains are used in heavier-duty applications.
  
• Gauge: The thickness of the drive link. CJX73 uses a .058" gauge, while CJX75 uses .063".
  
• Kerf: The width of the cut made by the chain. Though not officially published by Oregon, users report that the CJX series cuts a kerf similar to .404" chains due to its wide cutter tooth design.
  

Square-Ground Chisel and Skip-Tooth Configuration

• Square-Ground Chisel: A cutter profile with sharp, square edges that slices through wood fibers more efficiently than round-ground cutters. It requires precise filing but offers superior performance in clean wood.
  
• Skip-Tooth: A sequence where every other cutter is omitted, reducing drag and improving chip clearance. This is ideal for long bars and large-diameter timber, where heat buildup and clogging are concerns.
  

The CJX chains combined these features, making them a favorite among seasoned loggers. Their ability to stay sharp longer and maintain a wide kerf made them indispensable in high-volume felling operations.
Why the CJX Series Was Discontinued
Oregon phased out the CJX series due to manufacturing shifts and market consolidation. As demand for square-ground skip-tooth chains declined in favor of semi-chisel and round-ground profiles, production of niche chains like CJX73 and CJX75 became economically unsustainable. Additionally, newer chains with advanced coatings and self-sharpening designs began to replace traditional models.
Replacement Options and Compatibility Issues
Many professionals turned to the CJ73 as a substitute. However, the CJ73 lacks the wide cutter tooth of the CJX series and does not maintain sharpness as effectively in hardwood. Some users reported increased downtime due to frequent sharpening and slower cutting speeds.
Alternative chains include:

• Oregon 59CL and 59CK: .404" pitch, .063" gauge square-ground chisel chains with skip sequence.
  
• Stihl Rapid Super and Duro: Available in .404" pitch, designed for durability but may require additional lubrication in dense cuts.
  

Terminology Annotation

• Drive Link: The part of the chain that fits into the guide bar groove and engages with the sprocket.
  
• Cutter Tooth: The sharpened segment responsible for slicing through wood.
  
• Tie Strap: Connects drive links and cutter teeth, maintaining chain integrity.
  

Field Experience and Anecdotes
A veteran logger in New South Wales recalled using CJX73 for over 15 years, praising its performance in Australian hardwoods. When his supply ran out, he trialed the CJ73 but found it inadequate for the same tasks. He noted that the CJX chain’s kerf allowed for cleaner cuts and reduced bar pinching, especially in species like New England Blackbutt.
In the Pacific Northwest, old-school loggers reminisced about running .404" pitch chains on vintage saws like the Stihl 090 and Homelite 2100. These setups were common in the 1980s, when timber sizes demanded aggressive cutting tools. One technician recalled comparing cutter teeth side by side and confirming that the CJX’s tooth profile matched the kerf of .404" chains, despite its 3/8" pitch.
Recommendations for Professionals

• If CJX chains are unavailable, source old stock from specialty dealers or consider custom chain assembly using Oregon reels.
  
• For hardwood felling, prioritize square-ground chisel chains with skip sequence and wide cutter profiles.
  
• Maintain chains with precision filing tools and consider using a grinder for consistent angles.
  
• Increase bar oil flow when cutting dense wood to prevent overheating and premature wear.
  

Industry Trends and Logging Shows
At regional logging expos, such as the annual event in Eugene, Oregon, professionals gather to showcase innovations and reminisce about legacy tools. While modern chainsaws now feature electronic carburetors and anti-vibration systems, the nostalgia for chains like the CJX remains strong. These events often highlight the transition from brute-force cutting to precision forestry, where chain selection plays a critical role in efficiency and safety.
Conclusion
The Oregon CJX73 and CJX75 chains represent a bygone era of specialized logging equipment. Their unique combination of square-ground chisel cutters, skip-tooth configuration, and wide kerf made them ideal for demanding hardwood operations. Though discontinued, their legacy persists in the stories of loggers who relied on them daily. Understanding their design and performance helps inform better choices in chain selection, especially as forestry continues to evolve toward sustainability and precision.