Hydraulic Vs. Screw Jacks: What's The Difference Between These Mechanic Tools?

Hydraulic jacks and screw jacks serve the same basic purpose, allowing mechanics to lift and support heavy loads in the shop. That said, there are some pretty major differences in how they work, the way they perform, and when exactly they're used. From changing a flat tire at home to lifting an entire building, you should know which jack works best in each scenario so you can work smarter, not harder.

The biggest difference between hydraulic and screw jacks lies in how they actually generate their lifting power. Hydraulic jacks operate using Pascal's principle: That pressure applied to a confined fluid is transmitted uniformly in all directions. These jacks are made up of a hydraulic pump connected to one or more cylinders that are filled with oil. When pressure is applied (either via a lever or a motor), the fluid is forced into a larger piston chamber, causing the piston to rise and lift the load. Hydraulic jacks only need a small amount of input force to generate a massive amount of output force — in the greatest instances, up to 750 tons. 

On the contrary, screw jacks rely solely on mechanical power. These jacks lift as you turn a threaded rod via a ratcheting handle or a gear system. The rotational motion is converted into linear movement, which raises or lowers the load accordingly. Because of their self-locking threads, screw jacks can hold a load of over a hundred tons in place without continuous input or additional braking required.

Because hydraulic jacks can lift incredibly heavy loads with very little physical effort, they're super useful in heavy-duty industrial settings. (Think building bridges, constructing skyscrapers, or doing maintenance on large construction equipment.) They're also pretty popular for DIY engine maintenance. Many of these hydraulic systems are electrically powered, but that's not to say manual variants don't exist.

On the flip side, it's worth noting that hydraulic jacks need more maintenance than screw jacks. They're much more complex and, as such, require proper sealing and maintenance to prevent issues like fluid leakage or system degradation over time. They also aren't the best at holding heavy objects in place for extended periods of time because the hydraulic pressure can slowly start to release.

Screw jacks aren't as prone to failure from leaks or wear and tear, but they're also not built to hold as much as hydraulic jacks. Their lifting capacity also comes in much lower than their hydraulic counterparts. Still, their self-locking design means screw jacks can work horizontally or vertically, even after the operator lets go. Beyond the weight limit, the other main drawback of screw jacks is their slower lifting speed, as well as their need for manual input.

If you're working on a short task that requires some ultra-heavy lifting, a hydraulic jack is probably going to be your best bet. Its high efficiency, smooth operation, and larger weight capacity make it a great pick for industrial-grade jobs. These jacks come with trade-offs, like more maintenance and less long-term load support, but they still bring awesome power and precision when you need it most.

On the flip side, screw jacks work great when you need to hold a heavy load for extended periods with less risk of slipping thanks to their self-locking design. Screw jacks also require less frequent maintenance and can be a more cost-effective solution for lighter-duty or one-off lifting needs. In most everyday cases, hydraulic and screw jacks can be used interchangeably. Both work great as types of automotive jacks, too. Still, it's worth recognizing their individual strengths: hydraulic jacks bring more power and precision, while screw jacks offer more durability and less maintenance.