Standard UNI 699 precisely set the thread and ends of the wood screws. This is replaces the UNI 699:1980 from 18 november 2010.
What is the purpose of this standard?
As mentioned above this standard defines the thread and ends of the wood screws. Specifically those with thread size from 1.6 to 20 mm diameter, included.
DIMENSION | d₁ | d₃ | P |
TOLERANCE | h15 | h15 | ± 10% |
The designation.
How to make the designation? A thread of wood screws must be designated as follows:
- Thread diameter
- Refer to standard UNI 699
Let’s take a pratical example. If a thread of wood screw has a nominal diameter of 3 mm, i twill have this designation: “699 3 UNI tread”.
Some comments.
The UNI standard has a similar regulations in DIN 699. Does not seem to be present legislation (or similar) to the ISO. Therefore, at the international level it is logical to think that there is not a common guideline.