Stens 405-630 Blade Adapter, MTD 948-0323, ea, 1

What It Is

The Stens 405-630 Blade Adapter (equivalent to MTD 948-0323) is a replacement part that connects your mower blade to the crankshaft on select MTD, Craftsman, and Troy-Bilt walk-behind mowers. It’s used when the original adapter wears out or cracks, ensuring the blade stays secure and spins true.

Fitment & Compatibility

• Check your mower’s model number – This adapter fits most MTD, Craftsman (with 4-cycle engines), and Troy-Bilt push mowers made after 2000, but not all. Verify your OEM part number is 948-0323 or an equivalent like 405-630.
• Measure the crankshaft – It fits a 7/8-inch diameter crankshaft with a 3/16-inch keyway. If your shaft is 1-inch or has a different keyway, this won’t work.
• Deck size – Typically used on 21-inch to 22-inch decks, but not all. The adapter itself doesn’t dictate deck size—your blade and spindle do.
• OEM vs aftermarket – Stens is a reputable aftermarket brand; it’s a direct replacement for MTD 948-0323. No modifications needed.
• What to measure – The adapter’s center hole diameter (7/8”), overall length (about 2.5 inches), and the blade mounting hole pattern (usually a 5-point star). Compare to your old adapter.

Key Things to Know

• Quality – Stens is known for durable, heat-treated steel. This adapter is less likely to crack than some cheap no-name brands.
• Installation difficulty – Easy (15-20 minutes). Remove blade, slide off old adapter, clean crankshaft, install new one, and torque blade bolt to 30-40 ft-lbs. Use a thread locker.
• Common gotchas – The adapter can seize to the crankshaft if rusted; apply anti-seize during reassembly. Also, the blade bolt may be reverse-threaded on some MTD models (check before tightening).
• Pair with – A new blade and key if the old key is worn. Don’t reuse a damaged key.

Should You Buy It

If your MTD, Craftsman, or Troy-Bilt mower’s blade adapter is cracked, worn, or the blade wobbles, this Stens adapter is a solid, budget-friendly fix. It’s a direct fit for common 7/8-inch crankshaft models and holds up well. Avoid it if your mower uses a different shaft size or a non-MTD adapter.