Okay, that's a classic dilemma! Choosing between a rotary hammer and a dedicated demolition hammer, especially with SDS Max, really depends on your priorities and how you balance power, versatility, and budget. Let's break down the pros and cons to help you decide

Milwaukee 1 3/4" SDS Max Rotary Hammer (like the 5317-21 or similar)
Pros



Versatility

This is the big one. You can drill holes (for anchors, rebar dowels, coring) and use it for chipping. This is a huge advantage if you don't want to carry two tools or if you have limited space.

Controlled Power

Rotary hammers have a hammering action, but they also have a clutch and rotary function. This means you can dial down the power for more delicate tasks or when working close to finished surfaces.

Core Drilling Capability

The rotary function is essential for core drilling. If you anticipate doing any core drilling at all (for pipes, vents, etc.), this is a major advantage.

Generally Lighter & More Maneuverable

Compared to a pure demolition hammer, rotary hammers tend to be a bit lighter and easier to handle, especially in tight spaces.

Cons



Not Quite as Powerful for Demolition

While capable of chipping, it won't be as aggressive or as fast as a dedicated demolition hammer for heavy-duty material removal. You'll have to apply more pressure and/or make multiple passes in some situations.

Overheating Risk

Continuous, heavy chipping can overheat a rotary hammer faster than a dedicated demolition hammer, which is designed for sustained hammering. You'll need to be mindful of duty cycle and let it cool down occasionally.

Wear and Tear

Constantly switching between drilling and chipping can put more strain on the tool's mechanisms.

Milwaukee 1 3/4" SDS Max Demolition Hammer (like the 5446-21 or similar) Pros



Maximum Chipping Power

These are built solely for demolition. They deliver more impact energy (measured in foot-pounds or joules) and are designed for relentless hammering. This translates to faster material removal, especially in tough concrete or block.

Built for Sustained Use

Demolition hammers are built to withstand long periods of hammering without overheating. They have robust cooling systems and internal components designed for heavy-duty use.

Better Ergonomics for Demolition

The design is optimized for hammering, often with better vibration dampening and handle configurations for comfortable demolition work.

Cons



No Drilling Capability

Cannot drill holes. You need a separate drill for that.

Less Versatile

Only suitable for demolition. If your needs change on a job site, you're limited.

Heavier & Less Maneuverable

Demolition hammers are generally heavier and bulkier, making them harder to use in tight spaces or overhead.

More Expensive (Potentially)

While prices vary, a dedicated demolition hammer, with its specialized design, can be more expensive than a similarly sized rotary hammer. Factor in the cost of a separate drill, and the total investment goes up.

Here's How to Decide, Given Your Specific Use Case


Frequency of Core Drilling

If you do any core drilling on a regular basis, the rotary hammer is the clear winner. The ability to core is invaluable and saves you from needing a dedicated coring rig.2.

Proportion of Chipping vs. Drilling

Estimate the percentage of time you'll spend chipping versus drilling.

Mostly Chipping (70% or more)

If you primarily chip out block/concrete, the demolition hammer becomes a more compelling option. The speed and power advantage will save you time and effort, especially on larger jobs. Consider buying a smaller, less powerful drill for the drilling you need.

More Balanced (50/50 or less chipping)

The rotary hammer is likely the better choice. It provides sufficient chipping power for occasional tasks, while still giving you the crucial drilling/coring functionality.3.

Type of Concrete/Block



Standard Concrete/Block

The rotary hammer will likely be sufficient.

Hard, Reinforced Concrete

The demolition hammer will be much faster and more efficient.

Block

Depending on your skill and speed requirements, rotary should be sufficient.4.

Budget

If you can only afford one tool right now, the rotary hammer is the logical choice for its versatility. If you can budget for two tools (demolition hammer + drill), you'll have the best of both worlds: maximum chipping power and drilling capability.5.

Ergonomics and Job Site Conditions

Consider the typical job site conditions. Are you often working in tight spaces? Is weight a major concern? The lighter, more maneuverable rotary hammer might be better. If you are on a larger site or have dedicated space, then a demolition hammer may be okay.

Recommendation

Based on your description of "chipping out block/concrete for switch boxes and outlets" and dealing with "missed walls on underground foundations," my initial leaning is toward the

Rotary Hammer. Switch boxes and outlets generally don't require massive amounts of demolition. A rotary hammer should be sufficient for controlled chipping in those areas. Even for foundation work, while a demolition hammer might be slightly faster, the rotary hammer can still handle it. The ability to drill and potentially core drill outweighs the slight power advantage of the demolition hammer, especially if you only want to buy a single tool.

However, before making a final decision



Rent both a rotary hammer and a demolition hammer for a day and try them out on similar materials to what you'll be working with. This is the best way to get a feel for the power difference and see which tool better suits your needs. Consider a larger rotary hammer. Since you mentioned "solid block walls", if you are using this for a wall build out, then a larger rotary hammer may be a good idea. They generally have more power to get the job done. If you have the budget, start with the rotary hammer, and then* consider adding a demolition hammer later on if you find yourself constantly wishing you had more chipping power. This allows you to address your immediate needs with a versatile tool and then expand your capabilities as your business grows.Good luck with your decision! Flag for review