For many years, field drilling has been accepted as the standard approach across structural steelwork projects. It is familiar and widely understood, but it can also be slow, costly and full of potential risk.

Lindapter has long promoted a better way. This time, the company measured the difference.

The problem with field drilling

Anyone who has worked on a structural steel project will recognise the challenges involved in a drilled and bolted connection.

The equipment is heavy, the process takes time and the margin for error can be significant. If a hole is drilled at the wrong angle, in the wrong position or to the wrong diameter, the cost and disruption of rework can quickly outweigh the original operation.

Despite this, field drilling remains common across much of the construction and fabrication industry. This is not always because it is the best option, but because it is familiar. The tools are known, installers are trained in the method and the process is often built into project schedules.

However, familiarity does not necessarily mean efficiency.

With labour costs rising, project timelines tightening and health and safety requirements becoming more demanding, the true cost of field drilling is increasingly clear.

Lindapter’s girder clamp systems remove the need for field drilling. They provide a fully adjustable, structurally sound and significantly faster way to connect steelwork without creating new holes.

The industry asked for numbers, so Lindapter carried out a measured comparison.

The test

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

The task was simple: install the same steel connection twice, using a four-bolt configuration. One connection was installed using traditional field drilling and bolting, while the other used Lindapter girder clamps.

The same steel, environment and 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 each step recorded on camera so the process was transparent and the results were clear.

The results were:

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

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

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

These figures are not estimates or projections. They are measured and documented results from a controlled comparison carried out with an independent fabricator under real working conditions.

What field drilling actually involves

The time difference becomes clearer when the full drilling process is considered.

Field drilling is not a single action. It is a sequence of steps, each requiring time, skill and accuracy, with several opportunities for error.

Equipment set-up

Before drilling can begin, a magnetic drill must be sourced, transported and set up.

This is a heavy, specialist piece of equipment. Moving it between connection points, particularly at height, creates a logistical challenge. It will often also require 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 starts.

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 a considerable amount of time.

Drilling

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

This process generates heat, noise and metal debris. It also creates metal dust, which presents a genuine health hazard for workers in the field.

Hot work compliance

Drilling into steel produces sparks.

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

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

Cleaning and debris management

Once drilling is complete, the hole and surrounding area must be cleaned.

Metal swarf and debris need to be removed. This is both a safety requirement and an additional time cost, particularly when working at height.

Coating rework

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

If left untreated, the hole becomes a potential point of corrosion.

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 project specification.

This adds further time and materials to the process.

Bolting up

Once the holes have been drilled, the connection can be bolted together, but only if the holes are correctly positioned, the right diameter and drilled at the correct angle.

If any of these points are wrong, the installation stops while the issue is assessed and a solution is agreed.

Rework

Pre-drilled steelwork must align accurately on site.

If holes do not line up because of fabrication tolerance, site movement or measurement error, the options are limited. Reworking holes in structural steel on site is costly, disruptive and, in some cases, not possible without replacing the steel member.

The disadvantages of field drilling

The cost of choosing a drilled connection over a clamped connection is not limited to drilling time.

Field drilling often requires expensive, specialist equipment. A magnetic drill must be procured, transported, positioned and maintained. On projects with several connection points at height, the logistical burden can be considerable.

The process is also time-consuming and expensive to correct if mistakes occur. Layout, marking, drilling and final bolting all introduce opportunities for error, and any mistake can result in major rework.

Errors in hole size, position or angle are particularly difficult to rectify. A hole drilled in the wrong place cannot simply be moved. In some cases, the options are to weld and re-drill or replace the member entirely.

Drilling can also weaken the structural integrity of the steel. Every hole reduces the cross-sectional area of the member and therefore affects its load capacity. While this may be accounted for in the design, it remains an irreversible alteration.

The process also creates metal swarf, dust and coating damage. These hazards must be managed safely, and every damaged coating requires attention to prevent future corrosion.

In addition, field drilling may require an external power source, adding further site logistics. Although battery-powered magnetic drills are available, many operations still rely on mains power or generators.

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 secured.

This creates several key advantages.

Fully adjustable connections

The position of a Lindapter connection can be set, checked and adjusted before it is locked off.

There is no commitment to a final position until the installer is satisfied, unlike pre-drilled steel, where hole positions are fixed.

No field drilling

By removing field drilling, Lindapter eliminates one of the largest sources of time, cost and risk in a drilled connection.

No weakening of existing steelwork

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

Nothing is removed and nothing is altered.

No coating repair

As no holes are drilled, protective coatings remain intact.

This avoids introducing new corrosion points during installation.

No magnetic drills

Set-up, positioning, drilling and debris management are removed from the process.

The installer can complete the connection using hand tools.

No external power source

Lindapter connections do not require power.

This can be particularly useful on remote sites, heritage structures and occupied buildings where running power to the connection point may be difficult or impractical.

No incorrectly drilled holes

The connection is made to the steelwork as it stands.

Dimensional differences, fabrication tolerances or site movement can be accommodated through the adjustability of the system.

No metal dust

With no drilling, cutting or grinding required, there is no metal dust or swarf to manage.

The numbers at scale

A saving of 16 minutes on a single connection is significant. Across a larger project, that saving becomes far more substantial.

The measured comparison showed Lindapter girder clamps reducing installation time from 18 minutes 05 seconds to 2 minutes 24 seconds on a single four-bolt connection.

In practice, the real-world difference between drilling and clamping can be even greater.

Drilling fatigue, bit wear, moving equipment, managing power cables, working at height, shift handovers, fire watch arrangements and hot work permits can all add further time to drilled connections.

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 significantly reduced.

A wider industry argument

The construction and fabrication industry is under pressure.

Labour costs are increasing, skilled workers are harder to find and retain, project schedules are tighter and health and safety compliance is under greater scrutiny.

Against this background, reducing field drilling where structurally appropriate is not only a commercial decision. It is also a risk management decision.

Every hot work permit represents liability. Every operative using a magnetic drill at height creates a safety exposure. Every incorrectly drilled hole creates a programme risk. Every missed coating repair can become a long-term asset issue.

Labour is one of the largest costs on most structural steel projects, and time is one of the most limited resources on any construction programme.

Lindapter girder clamps are not simply a faster connection method. They offer a more efficient and lower-risk way to connect steelwork where the application is suitable.

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