PICHI sells its G9 slide-out utility knife in titanium, brass, and aluminum. I bought the aluminum first, then the brass, and the brass is the one that leaves the house. On paper they are the same 80 mm body, the same three-position lever, the same trapezoid blade. What changes is the metal, the finish, and roughly three times the weight. Here is what that difference means in a pocket, and what the maker's own numbers say.
The one I carry. 110 g (3.88 oz) on PICHI's spec page, in the same 80 mm body. Bare brass, sold on the way it darkens and mottles with handling, which is what brass does. In the pocket the weight is negligible; in the hand it feels superb.
For: most people. A buy-for-life knife that gets better with age and goes through boxes like a laser beam
Skip if: fingerprints and tarnish would bother you more than they charm you, or you want the lightest one
Check price on AmazonThe light one: 33 g without a blade, 37 g with, per PICHI, about a third of the brass. 6061 aluminum under a sealed hard-anodized finish, so sweat and a damp pocket do nothing to it. Mine is the green one, bought to match my wallet. I barely carry it.
For: anyone who wants the lightest G9 in a bright color and either does not mind scratches or will protect it
Skip if: the first scratch would bother you. The color lives in the finish and does not come back
Check price on AmazonWhy aluminum first. I initially got the aluminum. I love the color and thought it would match with my EDC. I have an Ekster Senate Cardholder wallet and the Cardholder Pro, in black and in forest green. I thought the greens would match up very well, from the knife to the wallet.
What it gets right. Initially, I was very happy with it, especially the subtle sliding sound when opening. It's fun, fidgety, and very well designed, with beautiful engineering and no blade play, due to those strong magnets that hold the blade in place.
Why I bought the brass. I liked it so much, but I also wanted to test out something more durable, since I was worried the scratches on the aluminum version would quickly make it look old. Also, I didn't want to worry about it getting scratched, so I thought, why not get a metal that actually improves with age, like brass? Also, with such a small knife, the actual weight is negligible in the pocket, but in the hand it feels superb.
What I carry now. I barely carry the green nowadays. I love carrying the brass. It's like a laser beam through boxes, and typically when you use a regular knife, it's never razor sharp for long. Whereas with this knife, I can change the blades often, since they're so cheap, and always have something incredibly sharp and effective in my pocket, for finer cuts, etc.
My pick. It's beautiful, useful, fun to hold and fidget with. It's durable. It's a buy-for-life type product, so I would strongly recommend the brass over the aluminum, for those reasons. If you prefer a lightweight knife with pretty colors, and you don't mind if it gets scratched, or you'll be sure to protect it, then you can go with aluminum. But for most people, I think go with the brass or titanium version: a bit pricier, but it will last forever and get better with age.
The G9 is not a folding knife. It is a two-piece metal body that carries a standard trapezoid utility blade on a track. PICHI's product page calls the action a gravity-driven slide: spread the two halves slightly, tip the knife, and the blade runs out; tip it the other way and it runs home. A small lever gives three positions: locked with the blade secured inside, a blade-change position at full spread, and a cutting position.
Gear Patrol's Sean Tirman covered the titanium original when it was a Kickstarter project in March 2024. He described the same three-step deploy: part the scales, slide the blade forward, close. The lever is marked Activate, Swap, and Lock. Yanko Design's write-up adds that magnets pull the halves back together and that a blade can be flipped end for end to use its second edge. That last part is true of any two-ended trapezoid blade.
PICHI DESIGN is a Canadian company; its site says the knife is made in Canada and that the mechanism is patented. The aluminum page names the alloy as 6061 under a sealed, hard-anodized finish, in black, green, blue, and orange. The brass page lists the metal only as brass and sells it on the patina it will develop.
One line from the listings worth repeating: both say a small amount of blade play is inherent to the design, and that the knife is meant for daily light cutting, not heavy industrial use. My aluminum has not read the listing. Those strong magnets hold the blade in place with no blade play, and daily light cutting is all I ask of either.
| Spec | Brass G9 | Aluminum G9 |
|---|---|---|
| Listing | ASIN B0GGV3499Y, style "Brass G9 ONLY" | ASIN B0GKB1PHD1, style "Aluminum G9-Black" |
| Body metal | Brass; alloy not named. The listing's "Grade 5 Brass" is a titanium designation carried over from the titanium listing, not a brass one | 6061 aluminum, per PICHI's site |
| Finish | Bare brass, meant to patina (PICHI) | Black hard-anodized, sealed (PICHI); the maker's site also lists green, blue, and orange |
| Weight, as listed | 110 g / 3.88 oz on PICHI's site. The Amazon bullet quotes the titanium's 55 g instead | 33 g without blade, 37 g with (PICHI); 33 g on Amazon |
| Size, as listed | 80 × 16 × 9 mm on the titanium/brass page; 3.14 in long on Amazon | 80 × 24 × 8 mm on the aluminum page; 8 cm long on Amazon. The two width figures disagree |
| Blade | Standard trapezoid utility blade; comes with 2 SK2 high-carbon blades | Same |
| Mechanism | Two-half body, blade slides on a track by gravity; three-position lever (locked / blade change / cutting) | Same |
| Blade change | Tool-free: lever to the change position, spread the halves, lift the blade base, swap (PICHI) | Same |
| Carry | No pocket clip listed; lanyard point at the hinge end; the leather holster is a separate purchase | Same; PICHI's own site bundles a TPU case, the Amazon package does not |
| In the box (Amazon) | Knife + 2 SK2 blades | Knife + 2 SK2 blades |
Two things in that table do not add up, and I am not going to paper over them. PICHI's titanium/brass page gives a 16 mm width and its aluminum page gives 24 mm for what is supposed to be the same body. A 19 mm-tall blade has to live inside it, so one figure is probably a different way of measuring, not a different knife. And the Amazon brass listing never states the brass weight. Its bullet quotes the titanium's 55 g and calls the body "ultra-lightweight," while PICHI's own site says 110 g. The listing copy came over from the titanium knife. The metal did not.
The arithmetic still says "same part, two metals." PICHI's weights come out to about 3.3 to 1. Wikipedia puts brass at 8.4 to 8.73 g/cm³ against 2.70 g/cm³ for 6061 aluminum, a density ratio of roughly 3.1 to 1. Identical geometry in two metals is exactly what that looks like. I have not put a scale or calipers on either; the numbers are PICHI's.
A utility knife is a blade holder. The edge is a disposable, roughly 0.65 mm-thick trapezoid you replace instead of sharpen. A pocket knife is a permanent blade you maintain. That one difference decides most of the rest.
The utility knife wins any job you would hate to do with an edge you paid to keep sharp: cardboard, packing tape, zip ties, clamshell plastic, scoring drywall, trimming carpet, scraping old gasket. The blade dulls, you flip it, then you swap it. There is no pivot to gum up and no edge to apologize for.
The folder wins anything that needs length or belly: food, wood, rope thicker than a blade is tall. It wins anything wet, because a carbon-steel utility blade left damp rusts. And it wins on carry, because it has a clip. The G9 has none. It rides loose or on a ring through the lanyard point at the hinge, which puts it closer to a keychain tool like the Bibury multitool than to a clipped folder. For the folder side of that line, my reference points are the Kizer Drop Bear, the Sheepdog Mini, and the head-to-head between them.
Brass is about three times as dense as aluminum, and PICHI's listed weights track that: 110 g against 33 g. For scale, the brass G9 outweighs a complete folding knife. Kizer's published spec for the Drop Bear is 3.28 oz; the brass G9 is 3.88 oz on PICHI's page. The aluminum G9 is about a third of that folder. In the pocket, I do not notice the difference. In the hand I do, and that is one of the reasons the brass is the one I carry.
Brass is a copper-zinc alloy, and copper reacts with what your hands and the air bring to it. Wikipedia's brass article describes the sequence. Copper reacts with sulfur to form a brown, eventually black, surface layer of copper sulfide. Only prolonged exposure to slightly acidic water takes that on to the green-blue copper carbonate of an old roof. Pocket carry gives you the first stage: dark where you grip, brighter where you do not. PICHI sells the brass on exactly this, promising "a rich patina" with time. Patina is tarnish you have decided to like. I have decided. If you would rather freeze the look, polish it back and coat it: the Copper Development Association's guide to clear organic finishes for copper alloys recommends lacquers formulated with a tarnish inhibitor such as benzotriazole. A wax does the same job for a while.
Anodizing converts the surface of the metal itself into aluminum oxide. The Aluminum Anodizers Council says that layer has much higher corrosion and abrasion resistance than the bare aluminum under it. The Aluminum Extruders Council notes it will not chip or peel, because it is grown from the part rather than painted on. The black is dye absorbed into the pores of that oxide and then sealed in. Sweat, salt, and a damp pocket do very little to it. PICHI's aluminum page describes the finish as sealed and multi-layer; I have no independent test of that claim.
Both metals feel cold at first touch, because both pull heat out of your skin far faster than wood or plastic. Aluminum does it faster: Wikipedia's list of thermal conductivities puts 70-percent-copper brass at 109 to 121 W/m·K and pure aluminum at 204 to 250, with 6061-T6 around 152. So the aluminum G9 reads colder in the hand than the brass one, and both read colder than a stainless folder handle (16 to 24 W/m·K on the same list). The "warmth" people attribute to brass is mostly color and patina, with a little physics behind it: it is not warm, it is less cold.
Brass is soft and malleable. The same Wikipedia article notes that higher-copper brasses are softer and that brass is more malleable than bronze or zinc. Drops leave dents, keys leave scratches, and both polish out because the metal is the same all the way through. Anodized aluminum resists scratching better, per the anodizers' own description above. But the color lives in the oxide layer. When a scratch does get through, it shows bright silver aluminum, and there is no home fix that re-blackens it. That is the scratch I was worried about when I bought the brass. My guess, not an observation: the sliding faces where the two halves rub are where the black wears first.
Both G9s take the standard trapezoid utility blade. PICHI's Amazon listings say "standard SK2 high-carbon steel blades," its aluminum page says the G9 is "designed for standard utility knife blades," and Gear Patrol confirmed standard-size blades on the titanium original. Both come with two SK2 blades and nothing else.
What "standard" means in numbers comes from Sollex, a Swedish blade maker, in its guide to utility blade types. The common trapezoid is about 59 to 60 mm long, 19 mm tall, and 0.65 mm thick, with two or three mounting slots along the top edge. A shorter 52 mm version also exists. Stanley lists its 1992 heavy-duty blade at 62 mm long and 0.024 in thick in high-carbon steel and says it fits most standard utility knives. That is the blade I would try first: Stanley 1992 heavy-duty blades, 100-pack with dispenser. I have not dropped one in yet, so whether the slot spacing agrees with the G9's blade base is Stanley's word and PICHI's, not mine.
PICHI also sells its own SK2 blade pack for the G9: trapezoidal, about 3 g per blade by the maker's figure. The maker claims more than three times the durability of a standard blade. Nobody I can cite has tested that, so treat it as marketing until someone counts cuts.
Other blade types exist, and I have checked none of them for fit. Hook blades for roofing and carpet are shaped differently and may not seat. Bi-metal and ceramic blades are out there too. Matt Higgins explains two edge treatments at Fine Homebuilding. One is a carbide edge, for hardness and edge retention. The other is the gold "titanium" blade, which is a thin titanium-nitride coating rather than titanium. SK2 is a plain high-carbon steel, so the included blades will rust if you put the knife away wet. Wipe the blade dry; the body does not care, but the blade does.
The opinion on this page is mine. The numbers are PICHI's. Here is what I have not done, so you can weigh that opinion accordingly:
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