Metabo HPT FAQ: What I Check Before Buying a Screwdriver, Nail Gun Battery, or 18V Air Compressor

I handle equipment maintenance and tool ordering for a five-person remodeling crew. Since 2017, I've made enough expensive mistakes to fill a small notebook. Realistically, they've cost us somewhere north of $3,200 in rework, return shipping, and one emergency rental that should never have happened. I started keeping these answers on a checklist so new people don't repeat my dumbest moves.

My experience is based on our mix of trim work, cabinets, and light equipment repair. If you're running a bigger industrial shop or a one-person side business, your experience may differ. When you need the official spec, look it up on metabo-hpt.com before you buy.

1. Wait, is it Metabo HPT or Hitachi?

Metabo HPT is the current North American name for what most of us still call Hitachi tools. The official website is metabo-hpt.com, and that hyphen matters when you type it. The tools still follow the same design approach: solid, pro-oriented, and built for daily work without a lot of unnecessary flash.

But here's the catch. Older Hitachi 18V batteries and newer Metabo HPT bare tools don't always mix. I bought a used Hitachi 18V pack once because it looked right in the photos. The tool manual listed compatible battery models, and mine was not on that list. The pack would not seat properly. It looked like a deal until I tried to use it. Before you buy any bare tool, check the manual's battery compatibility list first. That single step would have saved me most of the headache.

2. Which Metabo HPT screwdriver should a crew buy?

That depends on what you mean by screwdriver. For cabinet hardware, switch plates, and light assembly, a compact screwdriver or drill driver gives you better control. It runs slower, which sounds bad, but it stops you from stripping small screw heads.

For long deck screws, metal screws, and production work, get an impact driver. The pulsing torque does the hard work, and your wrist will feel better at the end of the day. If our crew only had one tool, I would pick the impact driver. But if you're doing finish work, the compact Metabo HPT screwdriver is easier to control. Either way, buy the bare tool if you already own 18V batteries. Sharing batteries across the platform makes that second tool much cheaper.

3. Which Metabo HPT nail gun battery do I need?

Most current battery-powered Metabo HPT nailers run on the same 18V MultiVolt battery family as the screwdrivers and drill/drivers. That's a strong reason to stay on one battery platform. But do not trust a listing that simply says it fits Metabo HPT.

I bought a used nailer that looked identical to ours. The manual specified a different battery revision than the one I had on hand, so I had to buy a new pack before the gun could work. The price difference between that used setup and a new kit was almost nothing by the end. If you are starting fresh, buy the kit with a battery and charger. If you already own the right packs, a bare nailer is a smart move. Just confirm the battery model in the manual before you order.

4. What can an 18V air compressor really run?

An 18V air compressor is convenient, but voltage does not tell you whether it can run a demanding air tool. The number that matters is CFM at the pressure you need, usually 90 psi.

A compact 18V air compressor is fine for topping off tires, blowing out dust, and running small brad or pin nailers. It is not a production compressor. I learned that by trying to run a hard-working nailer off a small battery compressor on a punch list. The pump cycled constantly and could not catch up. It worked, but barely. For light trim jobs, battery-powered air is fine. For all-day fastening, bring the larger compressor. Check the CFM rating before you assume the 18V battery system will make up for a small pump.

5. How do I find a 3100 psi pressure washer parts diagram?

Start with the data plate, not the psi rating. A 3100 psi pressure washer parts diagram is only useful when you are looking at the correct model and serial number. Most manufacturers post parts diagrams in their support or manual download sections. Metabo HPT follows that same approach for outdoor power equipment.

If the main brand site does not have the diagram, check the pump label. Pressure washer pumps are often made by specialist manufacturers, and those companies publish their own breakdowns. The diagram will list component numbers, so order by that number rather than by matching the shape with your eyes. I once ordered an o-ring kit based on what looked right. It was the wrong revision, and the replacement cost more than the original part would have. Data plate, diagram, part number. That is the order that works.

6. What size drill bit for a 3/8-18 NPT tap?

Use a 37/64 inch drill bit for a 3/8-18 NPT tap. That is the size on the standard tap chart in Machinery's Handbook. I still double-check it because instinct says a 3/8 pipe thread should use a 3/8 inch drill. It should not.

The NPT thread is tapered, not straight, and the tap cuts its full thread form only after entering the hole far enough. The drill bit needs to match the minor diameter of that tapered thread. If the hole is too small, the tap binds and can break. If it is too large, the fitting may leak. I made that mistake once, and extracting the broken tap took longer than the original job. Use cutting fluid, back the tap out often, and do not force it.

7. What should I check before assuming a tool is dead?

Check the simple things first. I have seen battery contacts cause more dead tools than actual motor failures. If a battery tool will not run, wipe the contacts and make sure the battery is fully seated. If a pressure washer will not start, check the GFCI outlet. If a nail gun stops firing, check the trigger lock and the battery charge level.

We did not have a formal pre-check process until 2024, when three separate problems in one month turned out to be basic issues. No parts were needed. Five minutes of checking beats five days of correction. That mindset is the entire reason I started writing this checklist, and it has saved us more money than any tool deal I have ever found.