A good fillet knife earns its place the moment you put it to a whole fish. It needs to be thin enough to feel the contours of the bone, flexible enough to follow the curve of a rib cage without tearing the flesh, and sharp enough to skin cleanly in a single pass. MAC has been making knives in Seki City since 1964, and the SO-70 is their answer to that specific brief — built from the same proprietary steel as the rest of the Professional line but shaped and ground for the particular demands of fish fabrication.
The blade is roll forged from MACs chrome-moly vanadium steel, an alloy engineered to achieve thinness and edge retention without the brittleness that compromises many hard stainless steels. At 2mm at the heel and just 4.1 oz total, the knife is notably light and flexible — thin enough to glide between flesh and skin with minimal resistance, with enough flex to track cleanly along pin bones and ribs on both round and flat fish. The blade profile is distinctive within the MAC lineup, narrower and more tapered than the petty or chef knives, and several reviewers note it doubles effectively as a short slicer for tasks beyond fish work. The bolster provides a well-balanced weight distribution that keeps the knife feeling controlled through the long, deliberate strokes that filleting requires. MAC backs this knife with a 25-year warranty against defects in materials and workmanship.
What Customers Are Saying: Reviewers with extensive knife collections describe this as one of the more underappreciated knives in the MAC lineup, noting that the blade geometry is unlike anything else in the range — thin to a degree that surprises even experienced cooks. Sharpness out of the box is consistently praised, with multiple owners describing clean first-use performance on whole salmon and various round fish. One long-term MAC collector with over thirty knives notes the balance at the bolster as particularly well executed, and several buyers mention the knife working equally well for slicing tasks beyond its intended fish work. CKTG service and same-day shipping are mentioned positively by name.
Care Instructions: Hand wash and dry after each use — this knife is not dishwasher safe. Rinse promptly after contact with fish and dry thoroughly before storing to maintain the edge and prevent any surface discoloration. The steel responds well to water stones and ceramic honing rods. The flexible blade requires care on the sharpening stone — maintain consistent angle and light pressure to avoid uneven wear. Avoid hard bones and frozen product.
The blade is roll forged from MACs chrome-moly vanadium steel, an alloy engineered to achieve thinness and edge retention without the brittleness that compromises many hard stainless steels. At 2mm at the heel and just 4.1 oz total, the knife is notably light and flexible — thin enough to glide between flesh and skin with minimal resistance, with enough flex to track cleanly along pin bones and ribs on both round and flat fish. The blade profile is distinctive within the MAC lineup, narrower and more tapered than the petty or chef knives, and several reviewers note it doubles effectively as a short slicer for tasks beyond fish work. The bolster provides a well-balanced weight distribution that keeps the knife feeling controlled through the long, deliberate strokes that filleting requires. MAC backs this knife with a 25-year warranty against defects in materials and workmanship.
What Customers Are Saying: Reviewers with extensive knife collections describe this as one of the more underappreciated knives in the MAC lineup, noting that the blade geometry is unlike anything else in the range — thin to a degree that surprises even experienced cooks. Sharpness out of the box is consistently praised, with multiple owners describing clean first-use performance on whole salmon and various round fish. One long-term MAC collector with over thirty knives notes the balance at the bolster as particularly well executed, and several buyers mention the knife working equally well for slicing tasks beyond its intended fish work. CKTG service and same-day shipping are mentioned positively by name.
Care Instructions: Hand wash and dry after each use — this knife is not dishwasher safe. Rinse promptly after contact with fish and dry thoroughly before storing to maintain the edge and prevent any surface discoloration. The steel responds well to water stones and ceramic honing rods. The flexible blade requires care on the sharpening stone — maintain consistent angle and light pressure to avoid uneven wear. Avoid hard bones and frozen product.
- Maker: MAC Knife, Inc.
- Location: Seki City, Japan
- Founded: 1964
- Construction: Mono Steel, Roll Forged
- Steel: Proprietary Chrome-Moly Vanadium
- Edge Grind: Double Bevel
- Blade Length: 170mm
- Total Length: 333mm
- Spine Thickness at Heel: 2mm
- Blade Height: 27mm
- Weight: 4.1 oz (115g)
- Warranty: 25 years against defects
Reviews
3 review(s) WRITE A REVIEW (Reviews are subject to approval) Excellent fillet knife Bloody good! Product ReviewPosted By: Dennis Pinto - verified customer
24 people found this review helpful
I recently purchased a MAC Professional Series 7? filet knife and wanted to write a review since there is nothing on the web about it. This is my seventh MAC, however I also have Shun, Moritaka, Takeda and Forschner. I think I have around 30 high-endish knives. I love my true Japanese Kuro-uchi knives but cutting through acidic foods (tomatoes and citrus fruits) leave the blade stained and uneven in color from base to tip. It does not effect the cutting ability but it just looks ugly. So I usually grab my Mac's for those jobs. Also, I rarely use my large knives (>7?) unless it's a slicer. Even my $200 MAC 10? Chef knife gets little use. So, I was looking for a knife to replace my German filet knife. Had my eye on this MAC Filet for years but had a hard time justifying the cost $145 new but can be had just about everywhere for $120. I didn't understand why cost so much more than other MAC blades in similar length. Until It arrived. First of all, the knife is very substantial. Significantly larger handle than their petty knives but what is more unique is the blade. It's impossibly thin. It's flexible but not flimsy. Balance at the bolster with a pinch grip right on. Definitely inspires confidence. I've never seen a profile quite like this either, leads me to believe that it could also be used as a short-slicing knife. They way that it sails through tomatoes with just a little puts a smile on your face. As I said, I love all of my knives but since little is written about this 7? Filet, I wanted to let everyone know this knife rules. Mark sent the knife out same day, free shipping and it arrived one day early. The thing I like about dealing with Chef Knives To Go is that Mark offer an unbiased opinion and stands behind his products.
24 people found this review helpful
I recently purchased a MAC Professional Series 7? filet knife and wanted to write a review since there is nothing on the web about it. This is my seventh MAC, however I also have Shun, Moritaka, Takeda and Forschner. I think I have around 30 high-endish knives. I love my true Japanese Kuro-uchi knives but cutting through acidic foods (tomatoes and citrus fruits) leave the blade stained and uneven in color from base to tip. It does not effect the cutting ability but it just looks ugly. So I usually grab my Mac's for those jobs. Also, I rarely use my large knives (>7?) unless it's a slicer. Even my $200 MAC 10? Chef knife gets little use. So, I was looking for a knife to replace my German filet knife. Had my eye on this MAC Filet for years but had a hard time justifying the cost $145 new but can be had just about everywhere for $120. I didn't understand why cost so much more than other MAC blades in similar length. Until It arrived. First of all, the knife is very substantial. Significantly larger handle than their petty knives but what is more unique is the blade. It's impossibly thin. It's flexible but not flimsy. Balance at the bolster with a pinch grip right on. Definitely inspires confidence. I've never seen a profile quite like this either, leads me to believe that it could also be used as a short-slicing knife. They way that it sails through tomatoes with just a little puts a smile on your face. As I said, I love all of my knives but since little is written about this 7? Filet, I wanted to let everyone know this knife rules. Mark sent the knife out same day, free shipping and it arrived one day early. The thing I like about dealing with Chef Knives To Go is that Mark offer an unbiased opinion and stands behind his products.
