MK Series (Standard Finish Mowers)

• Sitrex MK 150 (5 ft), MK 180 (6 ft), MK 210 (7 ft)
• Most popular Sitrex series in North America
• OEM blade: 612180 (6ft) / 512150 (5ft)
• Requires 25-50 HP tractor

SM Series (Economy Finish Mowers)

• Sitrex SM 150, SM 180 (5 ft and 6 ft)
• Entry-level Italian finish mower construction
• OEM blade: SM612180 (compatible with MK series)
• Requires 20-40 HP tractor

MP Series (Pro Finish Mowers)

• Sitrex MP 150, MP 180, MP 210 (heavy-duty series)
• Professional-grade deck construction
• Verify blade OEM number – may differ from MK series
• Requires 40-70 HP tractor

💡 Italian Mower Tip: Sitrex, Caroni, Maschio and New Idea all use common blade dimensions due to shared Italian manufacturing standards. If you find a blade listed for Caroni 71001000 or Maschio T14004010 – it very likely fits your Sitrex too! Always verify measurements before ordering.

🇮🇹 Sitrex → Caroni

Sitrex 612180 = Caroni 71001000 (6ft)
Sitrex 512150 = Caroni 59006200 (5ft)
Both Italian brands, same blade dimensions. Caroni blades widely available as direct fit.

🇮🇹 Sitrex → Maschio

Sitrex 512150 = Maschio T14004010 (5ft)
Maschio is another Italian manufacturer sharing common blade standards. Maschio blades are a reliable cross-reference option.

🇮🇹 Sitrex → New Idea

Sitrex SM612180 = New Idea SM612180
New Idea used Sitrex manufacturing for many models. Direct part number match in many cases – check your New Idea blade against Sitrex OEM number.

🔴 Problem: Uneven Cut Across Deck Width

Causes: One or more dull/bent blades, mismatched blade lengths across 3 spindles, worn spindle bearing causing blade height variation

Solutions: Replace all three blades as a set – never mix old and new. Verify all blades same length. Check each spindle bearing for wobble. Level deck side-to-side (measure deck height at all four corners).

🟡 Problem: Vibration After New Blade Install

Causes: Blades not balanced, incorrect blade length, blade installed upside down, loose blade bolt

Solutions: Balance all blades before installing. Verify correct blade length. Confirm cutting edge faces upward (toward deck). Torque blade bolt to spec. Run at low RPM first to verify smooth operation before full speed.

🔵 Problem: Blades Not Lasting Full Season

Causes: Cutting height too low, sandy/rocky conditions, mowing speed too fast, wrong blade grade for conditions

Solutions: Raise cutting height to minimum 3″. Reduce ground speed in rough conditions. Walk field for rocks before first cut. Sharpen regularly to maintain edge – dull blades require more passes and wear faster. Consider heavier gauge blades for abrasive conditions.

🟣 Problem: Bolt Seizing on Italian Mower

Causes: Metric bolts corroding in wet conditions, no anti-seize applied at previous installation, dissimilar metals causing galvanic corrosion

Solutions: Always apply anti-seize to blade bolt threads on Italian mowers – this is the single best preventive measure. If already seized: penetrating oil plus heat is most effective. Replace seized bolts with new Grade 8 metric hardware. Apply anti-seize at every blade installation going forward.

What blades cross-reference with Sitrex 612180?

Sitrex 612180 crosses directly with Caroni 71001000 and New Idea SM612180. These are all Italian-manufactured blades sharing identical dimensions. The XHT 3-blade set (available on Amazon) is manufactured specifically to fit Sitrex 612180, Caroni 71001000, and New Idea SM612180 – saving 35-45% versus OEM dealer pricing. Oregon and Copperhead also manufacture universal Italian finish mower blades that fit most Sitrex MK and SM series 6-foot models. Always verify blade length and center hole size match before ordering any cross-reference blade.

Why are Sitrex blades hard to find?

Sitrex is an Italian manufacturer with limited North American dealer network compared to American brands like Bush Hog or Land Pride. However, because Sitrex shares blade dimensions with Caroni, Maschio, and New Idea, sourcing replacement blades is actually easier than the limited Sitrex dealer network suggests. Search for Caroni 71001000 (6ft) or Caroni 59006200 (5ft) as cross-reference part numbers – these are widely available through Amazon, Stens dealers, and implement parts suppliers. The XHT blade sets are manufactured specifically for this Italian mower blade market and ship quickly.

How often should Sitrex spindle bearings be greased?

Grease Sitrex spindle bearings every 8-10 operating hours – more frequently than most American-made finish mowers. Italian finish mower spindles run at higher RPM and use smaller bearings than heavy-duty American designs, making regular greasing critical. Under-greased spindles are the leading cause of premature bearing failure on Sitrex, Caroni, and Maschio mowers. Use high-quality lithium-based or high-speed bearing grease rated for temperatures above 300°F. Each spindle has one or two grease zerks – locate and grease all of them. A seized spindle bearing ($21.50 to repair) from neglected greasing destroys new blades instantly – not worth the risk.

Are Sitrex finish mowers good quality?

Yes – Sitrex is a well-regarded Italian agricultural equipment manufacturer with decades of production history. Italian finish mowers are known for clean cutting performance, well-engineered blade geometry, and quality steel construction. Sitrex mowers perform comparably to American brands like Land Pride and Befco at often lower purchase prices. Main maintenance considerations: spindles require more frequent greasing than American mowers, metric hardware requires appropriate tool sets, and the limited North American dealer network means using cross-reference parts for blades and belts. With proper maintenance, a Sitrex finish mower provides 15-20+ years of reliable service.

What is the blade torque spec for Sitrex finish mowers?

Standard Sitrex finish mower blade bolt torque: 55-70 ft-lbs for most MK and SM series models using metric blade hardware. Always verify your specific model’s operator manual for exact specification. Italian mowers use metric bolts – typically M16 or M18 blade bolts. Apply anti-seize compound to threads at every installation – this is especially important on Italian mowers where bolt seizing is a common problem from moisture exposure. Replace blade bolts annually. Re-torque after first 2 hours with new blades. Check torque every 25 operating hours – vibration loosens hardware over time.