HKS Super Fire Racing Spark Plug 50003-M525RE
SKU: 76145787795

HKS Super Fire Racing Spark Plug 50003-M525RE

Sale price$57.28 Regular price$63.64
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Description

HKS Super Fire Racing Spark Plug 50003-M525REM Series Super Fire Spark Plugs HKS M Series spark plugs are high performance Iridium plugs designed to provide improved ignition performance, durability and anti carbon build up. 0. 6mm Iridium Alloy Center Electrode Outer Electrode with Platinum Chip Short Type Outer Electrode (Anti Vibration) Thermal Edge Spark Support Gap M Series is recommended for reliable ignition, durability and anti carbon buildup under high load. The Iridium alloy is used

M-Series Super Fire Spark Plugs

HKS M-Series spark plugs are high performance Iridium plugs designed to provide improved ignition performance, durability and anti-carbon build-up.

  • 0.6mm Iridium Alloy Center Electrode
  • Outer Electrode with Platinum Chip
  • Short Type Outer Electrode (Anti-Vibration)
  • Thermal Edge
  • Spark Support Gap

M Series is recommended for reliable ignition, durability and anti-carbon buildup under high load.

The Iridium alloy is used because of its durability and reliability.  On an average plug, a narrow core typically shortens life span of plug but with the intense durability of iridium there is no sacrifice in any longevity.  With a high melting point of 2454 degrees C, opposed to the 1769 degrees C of white gold, the electrode can tolerate the high levels of compression and minor knocking without any deterioration. A nickel coating on the housing also prevents the spark plug from premature deterioration.  The Iridium plugs are available for multiple applications and offered in "colder" heat ranges of 7 and up and specifically for rotary, heat ranges of 9 and up are offered.

Heat Range: NGK # 10.5
Thread Size: 14mm × 12.7mm
Wrench Size: 20.8mm

Fits:

1983 - 1985 MAZDA RX-7 ALL ALL From 10/1983 Thru 9/1985 Production Date  SA22C Chassis  Stock Plug/Heat Range: ROTARY:9
1985 - 1988 MAZDA RX-7 R2 1.3 From 10/1985 Thru 8/1988 Production Date  FC3S/FC3C Chassis  Stock Plug/Heat Range: ROTARY:10,11
1988 - 1991 MAZDA RX-7 R2 1.3 From 9/1988 Thru 12/1991 Production Date  FC3S/FC3C Chassis  Stock Plug/Heat Range: ROTARY:7,9
1993 - 1995 MAZDA RX-7 R2 1.3 From 12/1991 Thru 8/2002 Production Date  FD3S Chassis  Stock Plug/Heat Range: ROTARY:7,9
Shipping Notes
  • Free Standard Shipping on $100+ Orders to the USA.
  • Except Preorder products are shipped in 48 hours.
  • Delivery to the USA:
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Exchange/Return Notes
  • We offer a 30-day return/exchange service after receiving.
  • Final sale items are not eligible for returns or exchanges.
  • To process your return/exchange, please contact us at [email protected]
  • Please click here for more details>>> Return & Exchange Policy
SKU: 76145787795

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Raquel Hall
West Palm Beach, US
★★★★★ 4
Great fit but expensive
Size: Medium, Color: (252) Blush Beige / White / Castlerock
These are really great socks. I love them, but they are definitely pricey.
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Reviewed in the United States on March 30, 2026
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LacyConner
Bozeman, US
★★★★★ 5
Great socks!
Size: Medium, Color: (252) Blush Beige / White / Castlerock
Love these socks so much I got a second package. I like how thin and airy they are and they never slide down my heel. For thin socks they’re pretty durable.
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Reviewed in the United States on August 16, 2025
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Cor vW
Port Orchard, US
★★★★★ 5
Great
Size: Medium, Color: (001) Black / Black / Pitch Gray
The best pair of work / workout / casual socks I've bought in long time! They're no show on all my sneakers, incredibly comfortable and they never move.
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Reviewed in the United States on October 7, 2025
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Madison R.
Lowell, US
★★★★★ 5
Best no-show socks ever!
Size: 6-10, Color: Black
If you're tired of wearing socks that slip off and show in your sneakers, then you need to try these amazing socks! They are designed to stay in place, even after being active all day. They are incredibly soft and comfortable, and they are truly no-show, so you won't see them at all. I've been using these socks for years and have never had any issues. In fact, I love them so much that I've bought multiple packs, and my family members have started using them too. Don't waste any more time with those annoying socks that slip off and show - give these a try and you won't be disappointed!
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Reviewed in the United States on April 16, 2024
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Krissy
Massapequa, US
★★★★★ 5
The best
Size: 9-11, Color: Black
Seriously the best non slip low cut socks you can find. They stay in place all day and I love the fabric. They are thin which I prefer. These are really the only socks I wear.
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Reviewed in the United States on March 27, 2026

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