Search  for anything...

IRWIN Tools MARATHON Vinyl Siding Circular Saw Blade, 7 1/4-inch, 120T (21830ZR)

  • Based on 2,513 reviews
Condition: New
Checking for product changes
$14.79 Why this price?
Save $3.67 was $18.46

Buy Now, Pay Later


As low as $3 / mo
  • – 4-month term
  • – No impact on credit
  • – Instant approval decision
  • – Secure and straightforward checkout

Ready to go? Add this product to your cart and select a plan during checkout.

Payment plans are offered through our trusted finance partners Klarna, PayTomorrow, Affirm, Afterpay, Apple Pay, and PayPal. No-credit-needed leasing options through Acima may also be available at checkout.

Learn more about financing & leasing here.

Selected Option

Free shipping on this product

This item is eligible for return within 30 days of receipt

To qualify for a full refund, items must be returned in their original, unused condition. If an item is returned in a used, damaged, or materially different state, you may be granted a partial refund.

To initiate a return, please visit our Returns Center.

View our full returns policy here.


Availability: In Stock.
Fulfilled by Amazon

Arrives Sunday, May 18
Order within 16 hours and 19 minutes
Available payment plans shown during checkout

Size: 7-1/4" 120T


Style: Marathon


Features

  • Silicone coat allows the blade to slice easier through material reducing pitch and resin buildup when cutting pressure-treated lumber.
  • Construction-grade carbide teeth deliver longer blade life. Every other tooth is thinner for faster cuts.
  • The innovative heat vent/expansion slot design reduces vibration for longer life and straighter cuts. Plate is fully hardened to run truer, longer.
  • 120 tooth count with optimized, symmetric 60-degree tooth design is ideal for cuts to gutters, vinyl siding and PVC piping.

Material: Blend


Brand: IRWIN


Item Dimensions LxWxH: 7.3 x 7.3 x 0.1 inches


Color: Multi


Number of Teeth: 120


Style: Marathon


Item Weight: 8 Ounces


Number of Pieces: 1


Product Dimensions: 7.3"L x 7.3"W


Is Discontinued By Manufacturer ‏ : ‎ No


Product Dimensions ‏ : ‎ 7.3 x 7.3 x 0.1 inches; 8 Ounces


Item model number ‏ : ‎ 11870-P


Department ‏ : ‎ Unisex-Adult


Date First Available ‏ : ‎ February 22, 2012


Manufacturer ‏ : ‎ IRWIN


Country of Origin ‏ : ‎ China


Best Sellers Rank: #24,907 in Tools & Home Improvement (See Top 100 in Tools & Home Improvement) #244 in Circular Saw Blades


#244 in Circular Saw Blades:


Frequently asked questions

If you place your order now, the estimated arrival date for this product is: Sunday, May 18

Yes, absolutely! You may return this product for a full refund within 30 days of receiving it.

To initiate a return, please visit our Returns Center.

View our full returns policy here.

  • Klarna Financing
  • Affirm Pay in 4
  • Affirm Financing
  • Afterpay Financing
  • PayTomorrow Financing
  • Financing through Apple Pay
Leasing options through Acima may also be available during checkout.

Learn more about financing & leasing here.

Top Amazon Reviews


  • Worked well
Size: 6-1/2" 140T Style: Classic
Blade holds up well. No problem considering the reasonable price.
Reviewed in the United States on September 21, 2023 by Amazon Customer

  • Excellent for vinyl and plastic porch railings
Size: 10" 180T Style: Classic
Very good chop saw blade, no jagged cuts. I recommend this blade.
Reviewed in the United States on September 10, 2023 by B. K.

  • As advertised
Size: 10" 180T Style: Classic
Basic fine toothed blade. Works as expected so satisfied.
Reviewed in the United States on September 8, 2023 by Nelson G.

  • Makes cutting durock easier and cleaner
Size: 7-1/4" 4T Style: Fiber Cement
I used this blade with a corded SKIL 5280 7-1/4-Inch Circular Saw to cut backer board for a shower reno in my house. I cut mostly half inch and a few sheets of quarter inch Durock, total of about 12 sheets, but including a bunch of small pieces for a shower niche and a bench. I was on the fence about buying this because it's expensive (almost as much as the saw!) and because I had previously been able to do an adequate (but slow and painful) job cutting Durock using a razor knife (and a whole bunch of blades) on another job around the house. But I was looking for something that was (a) faster, (b) cut a cleaner edge and (c) didn't wear me out so much to use - so I took the leap. I'd say this blade fit all 3 counts. (a) It literally chews through Durock. Occasionally it'd hit a hard spot and would take a second to catch, but by and large the Durock was toast. It was really fast, it probably cut through a full 5' in maybe 10-15 seconds. This is several times faster than I can go with a razor knife (scoring, then cracking, then cutting again ...) - especially as those razor knife blades get dulled up after seems like just a couple cuts. (b) The edges were really clean. I clamped a guide board along the Durock to keep the saw straight, and it had absolutely no problem keeping straight. No waving edges to have to go back later and clean up in place. If you were really in a hurry, you could probably use it freehand, since it didn't struggle at all cutting the material. Overall those really clean edges made fitting them together much easier and greatly reduced the amount of time I had to spend scraping little protuberances to make all the sheets fit together. (c) I'm 39 - which I consider not real old, but also not real young, and anything I can do at this point to save my arm and shoulder some stress is welcome. This thing just took a lot of the effort out of the job. Hand cutting, especially with a dulled up razor, is something I'm happy to minimize. It just made it much less taxing of a job. The one blade lasted the entire job and I couldn't tell any difference in cutting from beginning to end. I'm assuming I'll be able to use it on my next project. There were a couple downsides: - It did make a lot of dust and blew bits of board off at high speed, and it was loud as all get-out. As others have said - wearing a mask, goggles and ear protection is a must. I did all the cutting outside the garage, I'm not sure I'd use it indoors unless it was really well ventilated. - It's expensive Overall, I would definitely buy again despite my angst at the price point. ... show more
Reviewed in the United States on November 6, 2019 by JRabbit

  • great value
Size: 10" 180T Style: Classic
thanks
Reviewed in the United States on August 12, 2023 by kenth c patterson

  • Cheap and good enough
Size: 10" 180T Style: Classic
I used these to cut baseboard and door casing. Once I moved to the laminate flooring the blade burned thru the cuts Smoking! Won't last long on anything dense. It's a cheap blade good for less than 1000 sq ft trim. That's all I needed!
Reviewed in the United States on April 4, 2023 by Taracha M

  • Works great!
Size: 10" 180T Style: Classic
Glad I found this seller. I have to cut an oak molding for my living room and was looking for a blade that isn't too expensive but works great! This didn't disappoint me. Thanks!
Reviewed in the United States on May 30, 2023 by Yza

  • Cut good
Size: 10" 180T Style: Classic
It’s what I expected for the price. Cut well on 1/8” Luan.
Reviewed in the United States on February 26, 2023 by Bill Blackburn

Can't find a product?

Find it on Amazon first, then paste the link below.