Grasscool 21" Medium-Lift Mower Blades for 42" Craftsman Decks — 5-Point Star Center, 7/8" Lift

Grasscool 138971 replacement blades are 21" medium-lift mower blades with a 5-point star center hole designed to fit 42" Craftsman, Poulan Pro and Husqvarna riding mower decks.

This set of Grasscool blades replaces OEM numbers like 138971, 138498 and equivalent part numbers for a 42" deck. Each blade measures 21" long, 2-1/4" wide and 5/32" thick, with a 5-point star center hole and 7/8" lift—specifications made to restore cutting performance on compatible models such as Craftsman LT1000/LT2000/T110 series, Poulan Pro PP19A42, and Husqvarna YTH18542. The edges are painted to reduce corrosion and to protect hands during installation; paint will wear with use and blades can be sharpened for a finer finish.

How do I confirm these blades will fit my mower?

Before ordering, verify the center hole shape on your current blade—Craftsman decks used two different star sizes. These Grasscool blades use a 5-point star center hole; if your blade has a 6-point star you need a different part number. Also measure blade length to ensure a 21" replacement suits your 42" deck.

• Center hole: 5-point star (this product)
• Blade length: 21" (533 mm)
• Blade width: 2-1/4" (57 mm)
• Check OEM numbers: 138971, 138498, 532127843, 532138971

What cutting performance and deck results should I expect?

These medium-lift blades balance grass lift and ejection—good for bagging, side discharge and mulching when used with the right deck setup. The 7/8" lift helps send clippings into a bagger or out the side, while the heavier 5/32" thickness resists bending in tougher conditions. For manicured lawns, sharpen blades regularly to maintain a clean cut.

• Lift height: 7/8" for improved clipping flow
• Thickness: 5/32" for durability on rougher terrain
• Medium-lift design: works with bagging and discharge systems
• Edges painted: temporary corrosion resistance and safer handling

Are these blades durable and safety-tested?

Grasscool subjects its blades to mechanical and field testing to ensure reliable performance. Tests include hardness, bend, chip resistance, balance and real-world cutting trials. Proper installation, periodic inspection and sharpening extend blade life and preserve cutting quality.

• Rockwell hardness testing and V-bend resilience checks
• Balance and chip-resistance verification for consistent rotation
• Field performance trials simulating mowing conditions
• Painted edges for temporary rust protection and safer handling

How do I install and maintain these replacement blades?

Installation follows your mower manufacturer’s instructions: disconnect spark plug, raise mower, remove spindle hardware, swap blades and torque fasteners to spec. Maintain by checking balance after sharpening, tightening mounting bolts, and replacing blades that show cracks or excessive wear. Wear protective gloves and eye protection when handling and installing blades.

• Always disconnect spark plug before service
• Torque blade bolts to the mower’s specified setting
• Sharpen evenly and re-balance blades after grinding
• Replace if bending, cracking or deep nicks occur

Who is this for? These Grasscool 138971 21" medium-lift blades suit owners of 42" Craftsman, Poulan Pro and Husqvarna riding mowers who need a direct-fit, rugged replacement with a 5-point star center hole. Ideal for users who bag or discharge clippings, mow mixed or overgrown turf, and value tested durability. If you have a 6-point star center hole or a different deck size, choose the correct OEM-specific blade instead.