For many years, the structural steel industry has accepted field drilling as the default method. It is familiar, well established and widely understood, but it is also expensive, time-consuming and full of potential risk.

Lindapter has long argued that there is a better way. This time, the company measured the difference.

The problem the industry has been living with

Anyone who has worked on a structural steel project will understand the reality of a drilled and bolted connection.

The equipment is heavy, the process is slow and the margin for error is significant. If a hole is drilled at the wrong angle, in the wrong position or to the wrong diameter, the cost of rework can quickly become greater than the cost of the original operation.

Despite this, field drilling has remained the preferred method across much of the construction and fabrication industry. This is not necessarily because it is the best solution, but because it is the familiar one.

The tools are known, the workforce is trained in the method and the process is already built into many project schedules.

However, familiarity is not the same as efficiency.

In an industry where labour costs are rising, project timelines are tightening and health and safety requirements are increasingly demanding, the true cost of field drilling has never been higher.

Lindapter’s girder clamp systems remove the need for field drilling, providing a fully adjustable, structurally sound and significantly faster method of connecting steelwork without introducing a single new hole.

The industry asked for the numbers, so Lindapter measured them.

The test

Lindapter set up a controlled, like-for-like comparison using an independent fabricator.

The brief was straightforward: install the same steel connection twice, using a four-bolt configuration.

One connection was installed using traditional field drilling and bolting. The other was installed using Lindapter girder clamps.

The same steel, the same environment and the same starting point were used for both methods. The datum line for the top of the new steelwork was pre-marked on both sections to ensure consistent alignment.

The only variable was the connection method.

Both installations were timed from start to finish, with every step captured on camera so the process was transparent and the results were clear.

The result was:

• Traditional drilling and bolting: 18 minutes 05 seconds
• Lindapter girder clamps: 2 minutes 24 seconds

That represents a time saving of 16 minutes on a single four-bolt connection.

Lindapter was eight times faster, reducing installation time by 87%.

These were not estimated figures or projections. They were measured and documented results from a controlled comparison using an independent fabricator, carried out under real working conditions.

Breaking down the drilling process

To understand why the time difference is so significant, it helps to look at what field drilling actually involves.

It is not a single action. It is a sequence of steps, each taking time, requiring skill and introducing the possibility of error.

Equipment set-up

Before drilling can begin, the team must source, transport and set up a magnetic drill.

This is a large, heavy and specialist piece of equipment. Moving it between connection points in the field, particularly at height, creates a logistical challenge in itself.

In many cases, it also requires a power source, which may mean running cables or positioning a generator on site.

Layout and marking

Each hole must be accurately marked before drilling begins.

This involves measuring, marking and checking positions across all connections. Any error at this stage can affect every following step.

On a complex frame with multiple connections, this process alone can take up a significant amount of time.

Drilling

The magnetic drill is positioned, secured and used to bore the full-diameter hole through the steel.

This generates heat, noise and significant amounts of metal shavings and debris. It also produces metal dust, which presents a genuine health hazard to workers in the field.

Hot work compliance

Drilling into steel produces sparks.

On many sites, this classifies the operation as hot work, requiring a permit before work can begin.

If the building or structure does not have a fire protection system in place, a dedicated fire watch operative may also be required throughout the work, adding another person, another cost and another logistical requirement.

Cleaning and debris management

Once the hole has been drilled, the hole itself and the surrounding area must be cleaned.

Metal shavings and debris need to be removed. This is a safety requirement, as loose metal particles are sharp, dangerous and a hazard underfoot, particularly when working at height.

It is also another time cost that rarely appears clearly on a project schedule, but still affects the job.

Coating rework

Every hole drilled through galvanised or painted steel breaks through the protective coating.

If left untreated, this creates a vulnerable point where corrosion can begin and worsen over the life of the structure.

Standard practice requires every drilled hole to be touched up using a suitable coating, such as zinc-rich paint, cold galvanising compound or intumescent coating, depending on the specification.

Again, this takes time and materials, and it can easily be overlooked when schedules are under pressure.

Bolting up

Once the holes have been drilled, the connection can be bolted together.

However, this only works if the holes are in the correct position, have the correct diameter and have been drilled at the correct angle.

If any of these conditions are not met, the schedule stops while the error is assessed and a remediation plan is agreed.

Rework

Pre-drilled steelwork arriving on site requires precise alignment.

If the holes do not line up due to fabrication tolerance, site movement or measurement error, the options are limited and none are quick.

Reworking holes in structural steel on site is costly, disruptive and, in some cases, simply not possible without replacing the steel member.

The disadvantages of field drilling

The cost of choosing a drilled connection over a clamped one builds up through every stage of the process.

Expensive specialist equipment

A magnetic drill is not a standard site tool.

It must be procured, transported to site, positioned and maintained. On projects with multiple connection points at height, the logistical burden can be considerable.

Time-consuming and expensive rework

Layout, marking, drilling and final bolting form a multi-step process.

Errors at any stage can require rework, which on structural steel can become a major schedule issue.

Errors are difficult to rectify

A hole drilled at the wrong angle, in the wrong position or to the wrong size cannot simply be moved.

The options are limited. The member may need to be welded and re-drilled, or replaced entirely.

Structural impact

Every hole introduced into a structural member reduces its cross-sectional area and therefore its load capacity.

This may be accounted for in the design, but it remains a permanent and irreversible alteration to the steelwork.

Metal dust, debris and coating damage

Metal shavings and dust are occupational health hazards and must be managed and disposed of safely.

At the same time, coating damage around every drilled hole creates a long-term corrosion risk if not properly treated.

Power requirements

Field drilling may require a power source.

Although battery-powered magnetic drills are available, they have limitations in terms of run time and output. Many operations still rely on mains power or generators, adding further site logistics.

The Lindapter approach

Lindapter girder clamps grip the flange of an existing steel section without modifying the steelwork.

There are no holes, no heat and no field drilling. The connection is made using standard hand tools and can be fully adjusted before being locked off.

The advantages are significant.

Fully adjustable

The position of a Lindapter connection can be set, checked and altered before it is secured.

There is no commitment to a final position until the installer is satisfied. Pre-drilled steelwork does not offer the same flexibility.

No field drilling required

The largest source of time, cost and risk in a drilled connection is removed from the process.

No weakening of existing structures

Because no new holes are introduced, the steel member retains its full cross-sectional integrity.

Nothing is removed and nothing is altered.

No coating repairs

Because no holes are drilled, protective coatings remain intact.

No new corrosion points are introduced by the connection process.

No magnetic drill labour

Set-up, positioning, drilling and debris management are all removed.

The installer can arrive with hand tools and leave with a completed connection.

No external power source

Lindapter connections require no power.

This is particularly useful on remote sites, heritage structures and occupied buildings where running power to a connection point may be impractical or impossible.

No incorrectly drilled holes

The connection is made to the steelwork as it stands.

Dimensional errors in fabrication or site movement do not prevent the connection being made, as they can be accommodated by the adjustability of the system.

No dangerous metal dust

There is nothing to drill, cut or grind.

The installer works with clean steel and clean tools throughout.

The numbers at scale

A saving of 16 minutes on a single connection is meaningful. Across a larger project, it becomes even more significant.

The measured results showed:

• Traditional drilling and bolting: 18 minutes 05 seconds per connection
• Lindapter girder clamps: 2 minutes 24 seconds per connection

These figures use the measured per-connection times. In practice, the real-world gap between drilling and clamping can be wider still.

Drilling fatigue is real. An operative using a magnetic drill at height on a multi-connection project may not maintain the same pace as in a controlled test environment.

Bit wear slows progress. Equipment must be repositioned. Power cables must be managed. Different installers work at different speeds, and handovers between shifts can add further delays.

Fire watch rotas may also need to be managed, and hot work permits may need to be renewed.

These factors do not affect Lindapter installation in the same way. The tools are lighter, the process is more consistent and the physical demand is far lower than drilling at height.

The gap between being eight times faster in a controlled test and the real-world advantage on a live project may therefore be even greater.

The wider industry argument

The construction and fabrication industry is under pressure.

Labour costs are rising. Skilled workers are harder to find and retain. Project schedules are tighter than ever. Health and safety compliance is more demanding, more closely scrutinised and more consequential when something goes wrong.

Against this background, the case for eliminating field drilling wherever structurally appropriate is not only commercial. It is also about risk management.

Every hot work permit represents liability. Every operative working at height with a magnetic drill represents a safety exposure. Every incorrectly drilled hole represents a schedule risk. Every missed coating repair creates a long-term asset management problem.

Labour is one of the biggest costs on most structural steel projects. Time is one of the most constrained resources on any construction schedule.

Lindapter is not just a faster connection method. It is a more cost-efficient one.

The industry asked for the numbers. Lindapter measured them, and the results speak for themselves.