How to choose an SDS-Plus rotary hammer: diameter, weight and use

If you need to drill concrete and masonry and fix anchors, a 26 mm SDS-Plus rotary hammer (many catalogues call it a rotary hammer, the Italian trade name is "tassellatore") covers most everyday jobs; choose a 32 mm model if the holes are larger or the work is continuous. In the collection the rotary hammers weigh from 2.4 to 4.2 kg and the cordless ones are 18 V. For chiselling you need a chipping hammer instead, or a rotary hammer that allows hammer-only mode.

The types

SDS-Plus is the quick plug-in shank system of light rotary hammers. With this shank you find several product families:

• SDS-Plus rotary hammers: the machine for drilling concrete and masonry. There are corded and cordless models, with different working modes: the simplest have two modes, others have three.
• Compact rotary hammers: shorter and lighter, for working in tight spaces or overhead.
• SDS-Plus chipping hammers: they work in hammer-only mode, to chisel, remove plaster or cut channels.
• Drill bits and chisels with an SDS-Plus shank: these are the consumables you fit on the machine.
• Adapters and extensions: used to fit chucks and tools with other shanks, for example an SDS-Max adapter, or to reach awkward spots with an SDS-Plus extension.

When SDS-Plus is no longer enough, for very large holes or for demolition, you move up to machines with an SDS-Max shank, to demolition hammers and, for heavy continuous work, to pneumatic or hydraulic drills, which need a compressor or a power pack. These are machines of a different category, which this guide does not cover.

How to choose according to the job

Job	What to take	Why
Fixing anchors in masonry and brick	26 mm rotary hammer	It is the diameter that covers the holes for the most common anchors, with a handy machine.
Reinforced concrete, repeated holes all day	32 mm rotary hammer, high power	It handles larger holes and heavy use. Versions with a dust extraction unit exist, which reduce dust.
Flat renovation, overhead work	Compact cordless rotary hammer	It weighs less and has no cable. At the end of the day you feel it in your arm.
Installations: openings and boxes in walls	Rotary hammer with bits of different lengths	You change bit in a few seconds thanks to the quick-change shank.
Carpenter or window fitter who also drills wood and metal	Rotary hammer with adapter chuck	In rotation-only mode, with the chuck, holes up to 26-40 mm in wood and 13-16 mm in metal, depending on the model.
Light demolition, channels	SDS-Plus chipping hammer	It works in hammer-only mode and is made for chiselling.
Site with many holes and no breaks	Corded model, or cordless with several batteries	You do not stop to recharge. With a cordless tool, keep a spare battery.

The features to look at

Shank

It must match the shank of the tool. The most frequent value is SDS-Plus; some products have SDS-Max instead (a shank for larger machines) or an internal thread, typical of chuck adapters. Before ordering bits or chisels, check the shank, not only the diameter.

Drilling capacity

In the collection you find capacities of 26-40 mm in wood and 13-16 mm in metal, referred to rotation-only use. For concrete, the figure that counts is the maximum diameter given in the model name, such as 26 mm or 32 mm. The high value is needed if you often drill large holes; if you mostly drill anchor holes, the smaller diameter is enough.

Weight

From 2.4 to 4.2 kg. If you work overhead or for hours, every kilo counts. If you drill downwards in concrete, a heavier machine works better because it rests on the workpiece.

No-load speed

It goes from 0-800 to about 1400 rpm. It is not the main figure for concrete, where the hammering counts, but it helps when you drill wood or metal.

Voltage and motor

Cordless models are 18 V. If you already have batteries from the same system, choose the same one, so the batteries are interchangeable. Some models are brushless, that is, with a motor without brushes, like the M18 BLH at 26 mm: no brushes to replace and, with the same battery, generally more work for each charge.

Noise

The sound power in the collection goes from 100.5 to 108.4 dB(A), the sound pressure from 89.5 to 97.4 dB(A). These are high values: ear protection is always needed, even for a few holes.

Article code and pack contents

The code is needed to order the right spare parts and accessories. Also look at what is in the pack: in some cases it is only the machine with the case, so check whether battery and charger are included.

Accessories and consumables: what to look at in the product page

In the collection, besides the machines, there are the parts that wear out or adapt. Product pages usually show the article code and the shank. Here is what you find, with the data from the product pages:

• Bits and chisels in a set: the SET punte e scalpelli SDS plus (code 430.104.15700) is a 10-piece set, with bits 6x160, 8x160, 10x160, 8x210, 10x210, 12x210, 14x210 and 16x210 mm and two chisels, 14x250 and 14x20x250 mm. The bits range from 6 to 16 mm in diameter.
• Single Milwaukee chisels: the SDS-Plus wing chisel has a 22 mm blade and 250 mm total length (code 4932479900); the mortar chisel has a 32 mm blade and 125 mm total length (code 4932472029). They are sold individually.
• Two-cutter bits: the Milwaukee SDS-Plus M2 2-cutter NG bit set (code 4932492116) has an SDS-Plus shank.
• Extension: the Prolunga SDS-Plus Milwaukee is 300 mm long, has an SDS-Plus shank and is sold individually (code 4932471153).
• Chuck and adapters: to drill wood and metal in rotation-only mode you need a chuck. The Mandrino a cremagliera attacco SDS plus (code 374.250.45000) has a 13 mm capacity. If you already have a chuck with a ½″ x 20 UNF thread, you need an SDS-Plus adapter such as the Adattatori per mandrini SDS-Plus ½″ x 20 UNF Milwaukee (code 4932367438) or the DeWalt DT7030 (code 380.000.07030). The collection also has an adapter for the FIXTEC and SDS-Plus system (code 4932379877) and one for bits with dust extraction (code 4932471160).
• Setting threaded rods: the Adattatore di posa SDS Plus RA-SDS Fischer is not for drilling. It is a mounting accessory for rods with a hexagonal end, with an SDS-Plus shank and internal thread, for setting RG M and FHB II rods with RM II, RSB, FHB II-P and FHB II-PF capsules. It is sold in a polybag of 1 piece (also with article 62420).

Before ordering an adapter, compare three things: the shank towards the machine, the thread or guide towards the tool, and the article code. Two similar parts may have a ½″ x 20 UNF thread or a FIXTEC guide, and they do not fit the same way.

Noise, vibration and dust: what the law requires

Anyone using a rotary hammer at work in Italy falls under Legislative Decree 81/2008, Title VIII. Three points to know before choosing the machine:

• Noise (Chapter II, which transposes Directive 2003/10/EC): the action values are 80 and 85 dB(A) of daily exposure, the limit is 87 dB(A) taking the protectors into account. From 80 dB(A) the protectors must be made available, from 85 they must be worn. With a sound pressure of 89.5-97.4 dB(A), as in the collection, the 85 dB(A) threshold can be exceeded in less than an hour of continuous use at the highest value: the real time of use must be assessed.
• Hand-arm vibration (Chapter III, which transposes Directive 2002/44/EC): the action value is 2.5 m/s² and the limit is 5 m/s², referred to 8 hours. The value of the individual model is in the manual: ask for it before ordering if you have to do the risk assessment.
• Dust: drilling concrete and masonry produces respirable crystalline silica dust, for which occupational exposure limits exist. This is why it pays to extract the dust at the source, with a model that has a dust extraction unit or with an adapter for bits with dust extraction, and to wear a mask with a suitable filter.

Common mistakes

• Choosing only by power: a 32 mm rotary hammer tires you more than a compact one in an hour of overhead work, and the compact one would have done the same job.
• Forcing the machine: pressing hard does not drill faster. Let the hammering do the work, with two hands and the side handle. If you push with all your weight the bit overheats and the machine struggles.
• Drilling without checking what is behind: with a detector, look for concealed cables and pipes before starting. It is a risk not to underestimate in walls.
• Forgetting to clean and grease the shank: the bit fits badly and wears out sooner.
• Using hammer action on wood or metal: for these materials you need rotation only, with the adapter chuck.
• Ordering an adapter by diameter alone: what counts is the shank, not the size.
• Not extracting the dust: drilling dust from concrete is harmful. Goggles, ear protection and dust extraction are not optional.

Frequently asked questions

What is the difference between SDS-Plus and SDS-Max?

SDS-Plus is the shank of light rotary hammers, SDS-Max that of larger machines. They are not interchangeable, but adapters exist to fit a tool on a machine with the other shank.

Are a "tassellatore" and a rotary hammer the same thing?

Yes. They are two names for the same tool: a hammer drill that combines rotation and hammering. In catalogues you find both.

Corded or cordless?

Cordless if you work on sites without a socket nearby or overhead; corded if you drill for a long time in the same place. A corded model like the PH 26 T does not have the battery life problem.

Can I drill wood or metal with a rotary hammer?

Yes, with an adapter chuck and in rotation-only mode, within the capacities of the model. If you often drill these materials, a drill is better.

Can I work without dust extraction?

You can, but the dust stays in the air. Some models, like the M18 ONEFHPXDEL at 32 mm, have an integrated dust extraction unit.

You find rotary hammers, bits, chisels and adapters in the SDS Plus Rotary Hammers and Bits collection: for advice on the right model or for a quote, write to the AMES technicians. For a 26 mm cordless model you can start from the M18 BLH.