Enter your observations
Use measurements you can verify. Unknown or unreadable details can be left unspecified where the tool allows it.
Additional observations
Ready when you are
Your results will appear here without reloading this page.
How to use this tool
- Photograph the screw head, thread, shank and location before moving a fastener.
- Record timber saw marks separately, including direction and spacing when visible.
- Select observed clues and enter notes about replacement or repair evidence.
- Compare the observations with cited specialist research; retain contradictory or uncertain observations.
What the result means
Fasteners and saw marks can provide evidence about manufacturing methods, but their usefulness depends on the specific feature and its context. Thread profile, head/drive style, nail form and timber-surface marks should be documented separately because a repair may use later hardware in an older object.
Historic furniture often includes replacements, reused parts and later surface work. The presence of a machine-made screw may tell you about an intervention rather than date the entire object. Saw marks may be smoothed, obscured, or made by different technologies that can look similar in photographs.
Limits and good practice
This tool does not provide a numeric date or authenticity verdict. Do not remove original fasteners or scrape timber to reveal marks without considering conservation impact. Compare multiple fasteners and several protected/visible surfaces; document exactly where each clue occurs.
References and further research
Frequently asked questions
Can one screw date a piece of furniture?
No. Screws may be replacements and broad head styles span many periods. Compare several clues and document where each fastener occurs.
Does a slot-headed screw mean the piece is old?
No. Slotted screws have been used over a long period and continue to be made. The exact thread and manufacturing details matter.
Can saw marks provide an exact year?
Usually not. Saw technology histories overlap geographically and surfaces can be planed, sanded or altered later.
What if different fasteners appear in the same object?
Record them separately. They may indicate repairs, reused timber or changes made at different times.
Should I remove a screw to inspect it?
Not without a reason. Removing a historic fastener can damage its slot, surrounding wood or original evidence.
What is the most useful documentation?
Close photographs, dimensions, exact locations, the condition of surrounding timber and source references tied to a specific fastener or tool mark.