# Identify this object: "H-P TOOL" **URL:** \ **Category:** Factual Questions\ **Created:** [April 30, 2017, 1:42am UTC](https://boards.straightdope.com/t/identify-this-object-h-p-tool/785548 "2017-04-30T01:42:54Z")\ **Posts on this page:** 20\ **Page:** 1
**Author:** ![toadspittle](https://avatars.discourse-cdn.com/v4/letter/t/c0e974/32.png) [@toadspittle](https://boards.straightdope.com/u/toadspittle)\ **Post date:** [April 30, 2017, 1:42am UTC](https://boards.straightdope.com/t/identify-this-object-h-p-tool/785548/1 "2017-04-30T01:42:54Z")
My dad was a US Navy aviator during the Korean War. He flew Corsairs. We were recently going through some of his old gear (flight suits, helmets, etc.) and came across [an object we could not identify.](https://www.dropbox.com/s/iyd7atz2b8sfq11/h-p-tool.jpg?dl=0) The only identifying mark is the text, “H-P TOOL”, stamped into the metal. We found it with his first aid/survival packs. It appears to have been part of a purely first aid kit (i.e., all medical stuff), not the survival kit, which also had non-medical items (like sunscreen, water purifying tablets, etc.). But the packs had been reshuffled over the years, so it may have been part of either one (or neither) and had just been stuck in there for convenience. He flew in Korea, but also flew in peacetime before and after, so it may have been from any time during the 1950s, more or less. He went into the medical corps at the end of his career, so I doubt he flew after 1960ish. A cursory Googling turned up nothing. Anyone recognize it? ---
**Author:** ![rsat3acr](https://avatars.discourse-cdn.com/v4/letter/r/a3d4f5/32.png) [@rsat3acr](https://boards.straightdope.com/u/rsat3acr)\ **Post date:** [April 30, 2017, 1:57am UTC](https://boards.straightdope.com/t/identify-this-object-h-p-tool/785548/2 "2017-04-30T01:57:04Z")
Used them when I flew helicopters in the Army 80-85. Called a Zeus tool. Used to open the fasteners that held the cowlings closed. ---
**Author:** ![Xema](https://avatars.discourse-cdn.com/v4/letter/x/9de053/32.png) [@Xema](https://boards.straightdope.com/u/Xema)\ **Post date:** [April 30, 2017, 2:08am UTC](https://boards.straightdope.com/t/identify-this-object-h-p-tool/785548/3 "2017-04-30T02:08:34Z")
Yes, it looks like a tool to operate [Dzus quarter-turn fasteners](https://www.southco.com/en-nz/product/hierarchy.html?hid=7345) (the slotted variety). Here’s what looks like a [current version of that tool](https://www.summitracing.com/parts/mor-71600?seid=srese1&cm_mmc=pla-google-_-shopping-_-srese1-_-moroso&gclid=CjwKEAjw85DIBRCy2aT0hPmS1jkSJAC1m9Uv9S1n_L1qLbGPAsMeR7yMJf5SIqqZq6lqLo_IUf08GxoCwqbw_wcB). ---
**Author:** ![rsat3acr](https://avatars.discourse-cdn.com/v4/letter/r/a3d4f5/32.png) [@rsat3acr](https://boards.straightdope.com/u/rsat3acr)\ **Post date:** [April 30, 2017, 3:14am UTC](https://boards.straightdope.com/t/identify-this-object-h-p-tool/785548/4 "2017-04-30T03:14:40Z")
> [@Xema](#): > > Yes, it looks like a tool to operate [Dzus quarter-turn fasteners](https://www.southco.com/en-nz/product/hierarchy.html?hid=7345) (the slotted variety). > > Here’s what looks like a [current version of that tool](https://www.summitracing.com/parts/mor-71600?seid=srese1&cm_mmc=pla-google-_-shopping-_-srese1-_-moroso&gclid=CjwKEAjw85DIBRCy2aT0hPmS1jkSJAC1m9Uv9S1n_L1qLbGPAsMeR7yMJf5SIqqZq6lqLo_IUf08GxoCwqbw_wcB). Thought the actual name was with a “D” but didn’t remember for sure ---
**Author:** ![LSLGuy](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/lslguy/32/5813_2.png) [@LSLGuy](https://boards.straightdope.com/u/LSLGuy)\ **Post date:** [April 30, 2017, 3:15pm UTC](https://boards.straightdope.com/t/identify-this-object-h-p-tool/785548/5 "2017-04-30T15:15:50Z")
Agree it’s a Dzus tool. The two lobes are of different radius to fit into different sized fasteners. Kinda like those half-assed slots in battery doors of handheld devices that are meant to be turned with a coin. ---
**Author:** ![toadspittle](https://avatars.discourse-cdn.com/v4/letter/t/c0e974/32.png) [@toadspittle](https://boards.straightdope.com/u/toadspittle)\ **Post date:** [April 30, 2017, 3:44pm UTC](https://boards.straightdope.com/t/identify-this-object-h-p-tool/785548/6 "2017-04-30T15:44:47Z")
Cool! Thanks, gang! ---
**Author:** ![Oddball\_92](https://avatars.discourse-cdn.com/v4/letter/o/b3f665/32.png) [@Oddball\_92](https://boards.straightdope.com/u/Oddball_92)\ **Post date:** [April 30, 2017, 11:33pm UTC](https://boards.straightdope.com/t/identify-this-object-h-p-tool/785548/7 "2017-04-30T23:33:38Z")
I used those in '71-'75 working on F-4 Phantoms. Dzus tool ---
**Author:** ![snfaulkner](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/snfaulkner/32/433_2.png) [@snfaulkner](https://boards.straightdope.com/u/snfaulkner)\ **Post date:** [April 30, 2017, 11:42pm UTC](https://boards.straightdope.com/t/identify-this-object-h-p-tool/785548/8 "2017-04-30T23:42:39Z")
**Identify this object: "H-P TOOL"** _glances at pile of Hewlett Packard technical manuals on desk_ _expects link to be a picture of himself_ ---
**Author:** ![JHBoom](https://avatars.discourse-cdn.com/v4/letter/j/13edae/32.png) [@JHBoom](https://boards.straightdope.com/u/JHBoom)\ **Post date:** [May 1, 2017, 2:27am UTC](https://boards.straightdope.com/t/identify-this-object-h-p-tool/785548/9 "2017-05-01T02:27:55Z")
Also known among an older generation of aircraft mechanics as a “Mickey Mouse”. ---
**Author:** ![Leaper](https://avatars.discourse-cdn.com/v4/letter/l/4bbf92/32.png) [@Leaper](https://boards.straightdope.com/u/Leaper)\ **Post date:** [May 1, 2017, 8:45am UTC](https://boards.straightdope.com/t/identify-this-object-h-p-tool/785548/10 "2017-05-01T08:45:30Z")
For future reference, there’s an entire subreddit (IIRC, What is This Thing) dedicated to identifying mystery objects like this. ---
**Author:** ![kaylasdad99](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/kaylasdad99/32/3398_2.png) [@kaylasdad99](https://boards.straightdope.com/u/kaylasdad99)\ **Post date:** [May 1, 2017, 11:43am UTC](https://boards.straightdope.com/t/identify-this-object-h-p-tool/785548/11 "2017-05-01T11:43:56Z")
> [@rsat3acr](#): > > Used them when I flew helicopters in the Army 80-85. Called a Zeus tool. Used to open the fasteners that held the cowlings closed. In the event of a need to bail out, or for some other reason? ---
**Author:** ![Chronos](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/chronos/32/134_2.png) [@Chronos](https://boards.straightdope.com/u/Chronos)\ **Post date:** [May 1, 2017, 12:26pm UTC](https://boards.straightdope.com/t/identify-this-object-h-p-tool/785548/12 "2017-05-01T12:26:39Z")
> [@](#): > > Quoth **LSLGuy** : > > Kinda like those half-assed slots in battery doors of handheld devices that are meant to be turned with a coin. Those slots are usually found on things that take button batteries, and the proper tool to open one is… a button battery. When you open it, you use the new battery you’re about to put in, and when you close it, you use the old battery you’re about to throw out. And if you don’t have a new battery, then why are you opening it? ---
**Author:** ![LSLGuy](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/lslguy/32/5813_2.png) [@LSLGuy](https://boards.straightdope.com/u/LSLGuy)\ **Post date:** [May 1, 2017, 2:44pm UTC](https://boards.straightdope.com/t/identify-this-object-h-p-tool/785548/13 "2017-05-01T14:44:03Z")
> [@kaylasdad99](#): > > In the event of a need to bail out, or for some other reason? No. These fasteners hold sheet metal cowling panels in place over engines and such. The idea is to be able to easily open them to inspect or repair what’s inside. While sitting on the ground. The tool is essentially a fancy screwdriver for turning these oddball “screws.” > [@Chronos](#): > > Those slots are usually found on things that take button batteries, and the proper tool to open one is… a button battery. When you open it, you use the new battery you’re about to put in, and when you close it, you use the old battery you’re about to throw out. And if you don’t have a new battery, then why are you opening it? My very most recent experience with one was that the relevant battery (bog standard CR2032) was too thick to engage the slot. It seemed designed for a US 25 cent piece. I agree they ought to be designed as you say. And sometimes even are. But not always. Unfortunately. ---
**Author:** ![Pasta](https://avatars.discourse-cdn.com/v4/letter/p/ecccb3/32.png) [@Pasta](https://boards.straightdope.com/u/Pasta)\ **Post date:** [May 1, 2017, 8:10pm UTC](https://boards.straightdope.com/t/identify-this-object-h-p-tool/785548/14 "2017-05-01T20:10:59Z")
> [@Chronos](#): > > Those slots are usually found on things that take button batteries, and the proper tool to open one is… a button battery. When you open it, you use the new battery you’re about to put in, and when you close it, you use the old battery you’re about to throw out. And if you don’t have a new battery, then why are you opening it? The overwhelming majority of the time I am opening it up to figure out what type of battery it takes so that I can pick one up the next time I’m passing a CVS or whatever. ---
**Author:** ![rsat3acr](https://avatars.discourse-cdn.com/v4/letter/r/a3d4f5/32.png) [@rsat3acr](https://boards.straightdope.com/u/rsat3acr)\ **Post date:** [May 1, 2017, 11:14pm UTC](https://boards.straightdope.com/t/identify-this-object-h-p-tool/785548/15 "2017-05-01T23:14:46Z")
> [@kaylasdad99](#): > > In the event of a need to bail out, or for some other reason? pre and post flight inspections ---
**Author:** ![Isilder](https://avatars.discourse-cdn.com/v4/letter/i/cc9497/32.png) [@Isilder](https://boards.straightdope.com/u/Isilder)\ **Post date:** [May 2, 2017, 1:04pm UTC](https://boards.straightdope.com/t/identify-this-object-h-p-tool/785548/16 "2017-05-02T13:04:17Z")
H.P. Wetmore Tools About H.P. Wetmore Since 1950’s, H.P. Manufacturing has offered quality products, technical advice and pro-active customer service for the aerospace, automotive, fastener and metal working industries. ---
**Author:** ![Gunslinger](https://avatars.discourse-cdn.com/v4/letter/g/4491bb/32.png) [@Gunslinger](https://boards.straightdope.com/u/Gunslinger)\ **Post date:** [May 2, 2017, 1:18pm UTC](https://boards.straightdope.com/t/identify-this-object-h-p-tool/785548/17 "2017-05-02T13:18:50Z")
> [@LSLGuy](#): > > My very most recent experience with one was that the relevant battery (bog standard CR2032) was too thick to engage the slot. It seemed designed for a US 25 cent piece. I have a 1915 Webley MkVI (the old British Service Revolver, seen in basically every WWI movie, Zulu, etc.) The one screw that gets the cylinder out for cleaning in the field is sized to be turned by the edge of a shilling coin (but an American nickel works if you’re not an Edwardian British officer). But yeah, all those battery doors and things are designed for coins, just a few happen to take a battery the same thickness. Source: I collect cameras and light meters, and so have come across a lot of those slots, all the same size (fits a US quarter but I suspect they were actually designed with Yen in mind, being mostly from Japanese companies), with wildly varying shapes and sizes of batteries underneath. Several even close the cover over a 9V. ---
**Author:** ![kaylasdad99](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/kaylasdad99/32/3398_2.png) [@kaylasdad99](https://boards.straightdope.com/u/kaylasdad99)\ **Post date:** [May 2, 2017, 9:41pm UTC](https://boards.straightdope.com/t/identify-this-object-h-p-tool/785548/18 "2017-05-02T21:41:52Z")
> [@kaylasdad99](#): > > In the event of a need to bail out, or for some other reason? > [@LSLGuy](#): > > No. These fasteners hold sheet metal cowling panels in place over engines and such. The idea is to be able to easily open them to inspect or repair what’s inside. While sitting on the ground. The tool is essentially a fancy screwdriver for turning these oddball “screws.” My initial reaction to this was “Why keep it in the cockpit?” > [@rsat3acr](#): > > pre and post flight inspections …and that cleared it up. Thanks to the both of you. 🙂 ---
**Author:** ![rsat3acr](https://avatars.discourse-cdn.com/v4/letter/r/a3d4f5/32.png) [@rsat3acr](https://boards.straightdope.com/u/rsat3acr)\ **Post date:** [May 2, 2017, 11:03pm UTC](https://boards.straightdope.com/t/identify-this-object-h-p-tool/785548/19 "2017-05-02T23:03:40Z")
I kept mine in one of the pockets of my flight suit ---
**Author:** ![Chronos](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/chronos/32/134_2.png) [@Chronos](https://boards.straightdope.com/u/Chronos)\ **Post date:** [May 2, 2017, 11:19pm UTC](https://boards.straightdope.com/t/identify-this-object-h-p-tool/785548/20 "2017-05-02T23:19:01Z")
I’m surprised the thread has gone as long as it has without anyone suggesting that it’s for opening bottles of brown sauce. [Next page](https://boards.straightdope.com/t/identify-this-object-h-p-tool/785548.md?page=2)