Dimensioning values guide
How to use dimensioning values for screws and fasteners
What dimensioning values actually tell you
Dimensioning values help you understand how a fastener performs in a calculated connection. On this page, we bring together the catalogue sections that cover Marutex design values, other self-drilling screws and screws in timber, so it is easier to identify the right resistance tables before you move further into project calculations.
The key is not just to read a number in a table, but to choose the correct failure mode, the correct substrate situation and the correct fastener family. That includes knowing when to check pull-through, pull-out, bearing, tensile or shear values, when the relation between t and t1 matters, and when timber rules differ from steel-sheet rules.
What is included in our dimensioning values guide
Failure modes and table logic
Start here when you need to understand which resistance you are actually checking. This part of the guide helps separate pull-through, pull-out, bearing, tensile and shear values, and makes it easier to read the tables correctly before you choose a fastener or compare alternatives.
See the failure modes, notation and Marutex table logic on page 104 in the catalogue
Marutex design values
Use the Marutex tables when the fastening is based on Marutex stainless self-drilling screws and the calculation needs values tied to the Marutex families themselves. This is the right place to compare type B, C, D, FC and E values, understand when interpolation is needed, and check combined loading logic.
See technical details and design-value tables for Marutex starting on page 104 in the catalogue
Other self-drilling screws
Choose this section when the fastener is not being dimensioned from the Marutex-specific tables. It brings together pull-through, pull-out, tensile, shear and bearing values for other self-drilling screws, and helps you see where washer diameter, static load and substrate strength affect the design value.
See design values for other self-drilling screws on page 105 in the catalogue
Screws in timber
Use the timber section when the fastener goes into wood rather than steel. Here the logic shifts to threaded length in timber, service class, load type and shear in wood, which makes it important not to apply steel-sheet values where timber rules are the governing case.
See pull-out and shear values for screws in timber on page 106 in the catalogue
Detailed dimensioning values in our catalogue
The catalogue below is the best place to compare the actual dimensioning values used for different fastening situations. Start with the Marutex section to understand the failure modes and the main resistance tables, then move into the pages for other self-drilling screws and screws in timber depending on the substrate and fastening family.
If the screw family is not fully decided yet, compare this guide with drilling capacity and clamp length. If the environment or substrate quality affects the choice, it is also worth reviewing corrosion classes, material quality and technical description.
Page 104 - Marutex design values, failure modes and combined loading
Page 105 - Other self-drilling screws, washer assumptions and resistance tables
Page 106 - Screws in timber: pull-out values and timber-specific design assumptions
Page 107 - Timber shear values and final notes for timber-related dimensioning
Need help interpreting the right dimensioning values?
Dimensioning values are easy to misread when the wrong failure mode, the wrong substrate thickness or the wrong fastener family is used as the starting point. The risk grows when Marutex tables, other self-drilling screw tables and timber values are mixed too early in the decision.
We help customers compare substrate type, t and t1, washer assumptions, fastener family and project conditions so the selected values match the real application instead of only looking correct in isolation.
What is the difference between pull-through, pull-out and bearing resistance?
They describe different failure modes, so they should not be treated as interchangeable values. Pull-through resistance concerns the sheet material under the head, pull-out resistance concerns the screw pulling out of the underlying material, and bearing resistance concerns how the connected sheet bears against the fastener in shear. The right value depends on how the connection is loaded and where failure is most likely to occur.
How do I know whether to use Marutex values or the tables for other self-drilling screws?
Use the Marutex values when the fastening is based on Marutex stainless self-drilling screws and you need the resistance data tied to those specific screw families. Use the tables for other self-drilling screws when the fastening does not belong to the Marutex design-value system. The first decision is therefore the fastener family, not just the substrate thickness.
What do t and t1 mean in the dimensioning tables?
t is normally the thinner connected sheet nearest the fastener head, and t1 is the thicker connected part or underlying sheet. That distinction matters because several resistance tables change depending on whether the connection is read as t = t1 or t1 ≥ 2.5t. If those thicknesses are misread, the chosen value can be wrong even when the correct screw family is used.
When do I need to use interpolation between t = t1 and t1 ≥ 2.5t?
You need interpolation when the actual connection sits between those two table conditions. In other words, if the thickness relation is not equal-sheet and not yet at the 2.5-times threshold, the table should not be read as a simple direct match. This matters especially in steel-sheet connections where the resistance changes with the relative thicknesses of the connected parts.
Do washer diameter, load case and material strength affect the dimensioning value?
Yes. The value in the table may depend on more than the screw diameter alone. On some pages, washer diameter changes the result, static load can require an adjustment, and substrate strength can also affect the usable value. That is why it is important to read the notes around the tables instead of only scanning the main numeric grid.
How are timber values different from steel-sheet values?
Timber values follow a different logic from steel-sheet dimensioning. In timber, the guide focuses on pull-out in wood, threaded length in timber, service class, load type and shear in wood. In steel-sheet connections, the focus is more often on pull-through, pull-out from the substrate, bearing failure and screw failure. The substrate therefore changes both the table and the interpretation method.
Can Unite help us interpret the right dimensioning values for a project?
Yes. We help customers review fastener family, substrate type, thickness relation, timber versus steel logic and related guide factors so the chosen design values fit the real connection. That is especially useful when the project includes several fastening situations and the wrong table could otherwise be applied too early.