Shop Tour: The Combination Square and Layout Tool Collection
This is a different kind of shop tour – not of a space, but of a collection: the finest layout tool collection assembled by a retired engineer who spent 40 years specifying precision instruments for aerospace manufacturing and has applied those standards to his woodworking shop. Every tool in this collection is either a vintage precision instrument or a current-production tool from a quality manufacturer, and every tool is tested against a known standard before it enters service. The collection represents the upper end of what woodworking layout tools can be.
The Combination Square Collection
The centerpiece is a Starrett No. 11 combination square set with a 12-inch blade – the standard against which all other combination squares are measured. The head is ground square to within 0.0005 inches over the full length. A Brown and Sharpe 12-inch machinist’s square (solid steel, ground, reference quality) serves as the ultimate reference for checking all other squares. Six additional combination squares in various sizes (4-inch, 6-inch, 12-inch, 18-inch) are calibrated against the Starrett reference and labeled with their measured error.
Marking Gauges
The marking gauge collection spans six tools: a traditional wooden marking gauge, a Veritas wheel marking gauge, a mortise gauge, a Japanese-style single-pin gauge with a rosewood body, a cutting gauge with a blade-style cutter, and a saddle square for marking around corners. Each tool is kept razor-sharp and set to its last-used setting – the owner documents frequent settings on cards hung with each tool, eliminating the need to re-measure common dimensions between sessions.
Straight Edges and Winding Sticks
Three aluminum straight edges in 24-inch, 36-inch, and 48-inch lengths are each tested for straight on a surface plate. Two winding sticks – matching pairs of aluminum bars used to detect twist in large panels – are matched to within 0.001 inches of parallel. These are the tools the owner uses to verify whether a workbench top is flat or a panel glue-up is free of twist.
Key Lessons
- Every tool in this collection was tested against a known reference before it entered service. The owner finds this non-negotiable – a square that looks right but isn’t actually square introduces error into every project that uses it.
- Testing your tools costs nothing except time. A known-flat reference (a properly calibrated surface plate, or even the blade of a verified straight edge) allows you to check every measuring tool you own for error.
FAQ
Is a Starrett combination square worth the cost for a home woodworker?
For someone who cares about layout accuracy, yes. The Starrett head is accurate enough that it serves as a reference for checking other tools. For general woodworking, a quality mid-range square (Shinwa, PEC, Empire) is more than adequate. The Starrett is for woodworkers who want to know their tools are right, not just hope they are.
How do I check if my combination square is actually square?
Scribe a line from a true edge using the square. Flip the square to the other side of the line and check whether the blade aligns with the original line. Any gap shows the square’s error – half the visible gap is the actual error in the square’s reference angle.