Sitrex Finish Mower Blade Cross-Reference Guide

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⚡ Quick Answer

Sitrex’s current finish mower lineup is the SM series (SM120 through SM230) — not “MK” or “MP” model names sometimes seen online, which don’t correspond to any current Sitrex finish mower. The two most common sizes, SM150 (5ft, blade 512150) and SM180 (6ft, blade 612180), both have real, well-reviewed aftermarket blade options that also cross-reference to Caroni and Maschio (for the 150) or Caroni and New Idea (for the 180). Always confirm your exact SM model number before ordering.

Sitrex Finish Mower Models & Blades

SM150 (5ft / 60″)

Blade: 512150 — 20-1/4″ long, .250″ thick, .750″ center hole

Also cross-referenced to Caroni 59006200 and Maschio T14004010

SM180 (6ft / 72″)

Blade: 612180 — 24-1/16″ long

Also cross-referenced to Caroni 71001000 and New Idea SM612180

⚠️ Key Point: Model names like “MK150,” “MK180,” or “MP” series aren’t current Sitrex finish mower designations — Sitrex’s own current lineup uses SM (SM120, SM150, SM180, SM210, SM230). If you’ve seen those other names referenced elsewhere, double-check your deck’s actual model tag against the SM series above before ordering a blade.

Sitrex Blade Cross-Reference Chart

Model	Blade #	Also Fits	Buy
SM150 5ft / 60″	512150	Caroni 59006200, Maschio T14004010	View on Amazon →
SM180 6ft / 72″	612180	Caroni 71001000, New Idea SM612180	View on Amazon →

💰 Cost Note: XHT’s blade sets for both SM150 and SM180 run $53-68 for a full 3-blade set — well-reviewed (4.7-4.8★) and manufactured to cross-reference Caroni, Maschio, and New Idea equipment sharing the same blade dimensions, so a single product often covers several brands at once.

Sitrex Spindle Care

Italian-manufactured finish mower spindles like Sitrex’s often need more frequent greasing than heavier American-built decks — check your zerk fittings every 8-10 operating hours rather than waiting for a scheduled service interval. A rough or wobbly spindle destroys a new blade quickly, so spin each spindle by hand after blade removal and before installing new blades — if it doesn’t turn smoothly, address the spindle first.

Complete Blade Replacement Guide

Safety Preparation

Disengage PTO completely and shut off the tractor. Remove the ignition key. Lower the mower to flat ground and allow all blades to stop fully — 3+ minutes. Engage the parking brake. Wear heavy leather work gloves throughout; finish mower blades stay sharp even when dull.

Access & Apply Penetrating Oil

Tilt the mower on its side for underside access. Locate all blade spindle assemblies. Spray penetrating oil generously on all blade bolts — Italian mower bolts are notorious for seizing from grass moisture and debris. Wait at least 15 minutes. Italian mowers often use metric hardware, so have both metric and standard wrench sets on hand.

Remove Old Blades

Use an impact wrench or breaker bar to break blade bolts loose. Insert a wooden block between the blade and spindle housing to prevent rotation. If a bolt won’t move, apply more penetrating oil, use torch heat on the bolt head only (never the spindle housing), or try an impact hammer. Inspect the spindle for wear once the blade is off.

Inspect Spindle Bearings

With the blade removed, spin the spindle by hand — it should rotate smoothly with no roughness or wobble. Roughness means a bearing needs replacing; wobble means the spindle assembly itself needs replacing. Always resolve spindle issues before installing new blades — a bad spindle destroys new blades within one season.

Install & Torque New Blades

Install new blades with the cutting edge facing the correct rotation direction. Install the blade bolt with a hardened washer. Apply anti-seize compound to bolt threads — critical for Italian mowers that tend to seize. Torque to 55-70 ft-lbs. Verify all blades are secure with no wobble. Re-torque after the first 2 hours of operation, then check every 25 hours.

Blade Troubleshooting Guide

Problem	Causes	Solutions
Uneven Cut Across Deck	Dull/bent blade, mismatched blade lengths, worn spindle bearing	Replace all blades as a set — never mix old and new. Verify equal blade lengths. Check each spindle for wobble. Level the deck side-to-side.
Vibration After New Blade Install	Blades not balanced, incorrect length, blade installed upside down, loose bolt	Balance blades before installing. Confirm cutting edge faces upward. Torque bolt to spec. Test at low RPM before full speed.
Blades Not Lasting Full Season	Cutting height too low, sandy/rocky conditions, mowing speed too fast	Raise cutting height to minimum 3″. Reduce ground speed in rough terrain. Walk the field for rocks before first cut.
Bolt Seizing	Metric bolts corroding, no anti-seize applied previously, moisture exposure	Always apply anti-seize on Italian mower blade bolts — the single best preventive step. If already seized, penetrating oil plus heat works best.

Seasonal Maintenance

🌱 Spring

Inspect blades for winter rust and damage. Sharpen to a 30-degree bevel. Check spindle bearings by hand. Grease all zerks. Verify deck level side-to-side.

🔧 Every 8-10 Hours

Grease all spindle zerks — Italian finish mowers typically need more frequent greasing than American-built decks. Under-greasing is the leading cause of premature spindle failure.

⚙️ Every 50 Hours or When Dull

Sharpen and balance all blades. Inspect spindle condition. Check deck hardware for looseness. Clean packed grass buildup from under the deck.

❄️ End of Season

Remove blades and store inside — Italian blades rust quickly outdoors. Heavy-grease all spindles. Clean the deck thoroughly and note any repairs for spring.

🔧 Complete Blade Kit

Replacement Blades

SM150 Blade Set (512150)

4.7★, also fits Caroni/Maschio

View on Amazon →

SM180 Blade Set (612180)

4.8★, also fits Caroni/New Idea

View on Amazon →

Affiliate Disclosure: We may earn a commission from qualifying purchases through these links at no extra cost to you.

Related Italian Finish Mower Guides

Caroni Belt Cross-Reference →

Compatible belt guide for Italian mowers

Befco Blade Guide →

C30/C50 OEM blade numbers

Finish Mower Gearbox Leaks →

Fix common gearbox issues

Maintenance Checklist →

Track all service intervals

❓ Frequently Asked Questions

What are the current Sitrex finish mower model names?

Sitrex’s current finish/grooming mower lineup is the SM series: SM120, SM150, SM180, SM210, and SM230, covering roughly 48″ to 90″ working widths. If you’ve seen “MK” or “MP” model names referenced elsewhere, those don’t correspond to any current Sitrex finish mower — check your deck’s actual model tag against the SM series before ordering a blade.

Do Sitrex blades really cross-reference to Caroni and Maschio?

For the SM150 and SM180 specifically, yes — well-reviewed aftermarket blade sets are sold explicitly listing both the Sitrex part number and the matching Caroni or Maschio/New Idea number together on the same product, backed by dozens of consistent buyer reviews. That’s a genuine, retail-verified cross-reference, not just a length/width coincidence. For other Sitrex models or other Italian brands, don’t assume the same cross-reference applies without checking — Italian equipment manufacturers don’t publish a universal shared blade standard.

How often should Sitrex spindle bearings be greased?

Every 8-10 operating hours — more frequently than most American-made finish mowers. Under-greased spindles are the leading cause of premature bearing failure on Italian-built finish mowers. Locate and grease every zerk fitting on each spindle, and spin the spindle by hand periodically to check for roughness before it destroys a blade.

What is the blade torque spec for Sitrex finish mowers?

Standard Sitrex blade bolt torque runs 55-70 ft-lbs for most SM series models using metric blade hardware — but always check your specific model’s operator manual for the exact spec. Apply anti-seize compound to threads at every installation, since bolt seizing from moisture is a common issue on Italian-built mowers. Replace blade bolts annually, re-torque after the first 2 hours with new blades, and check torque every 25 operating hours after that.

🚜 Own a Woods rotary cutter? See our complete Woods Rotary Cutter Blade Guide — verified OEM blade kits by model, replacement steps, torque specs, and troubleshooting.

🇮🇹 Own a Caroni finish mower? See our complete Caroni Belt Cross-Reference Guide — verified TC590/TC710 belt codes, genuine Maschio cross-reference, replacement steps, and troubleshooting.

🔩 Need a Befco belt? See our complete Befco Belt Cross-Reference Guide — verified C30/C50 OEM belt codes, replacement steps, and troubleshooting.

Affiliate Disclosure: We may earn a commission from qualifying purchases through these links at no extra cost to you.