Hello everyone,
I am currently dealing with the issue that, under heavier loads, the screws in Malm furniture (especially those that connect the parts) tend to loosen repeatedly. I am particularly interested in understanding why this happens, even though the screws are properly tightened with the correct torque.
I have the impression that the material or the design might not be optimal, or that there are other physical reasons why the screws loosen under dynamic loads. Factors such as vibrations, material fatigue, or the type of fastening might also play a role.
Can anyone provide well-founded information on this or share proven methods to prevent loosening under heavier loads? It would also be interesting to know if this is related to the wood joints being subjected to high levels of friction and deformation, causing the screws not to hold permanently.
Thank you for your help!
I am currently dealing with the issue that, under heavier loads, the screws in Malm furniture (especially those that connect the parts) tend to loosen repeatedly. I am particularly interested in understanding why this happens, even though the screws are properly tightened with the correct torque.
I have the impression that the material or the design might not be optimal, or that there are other physical reasons why the screws loosen under dynamic loads. Factors such as vibrations, material fatigue, or the type of fastening might also play a role.
Can anyone provide well-founded information on this or share proven methods to prevent loosening under heavier loads? It would also be interesting to know if this is related to the wood joints being subjected to high levels of friction and deformation, causing the screws not to hold permanently.
Thank you for your help!
N
narDietmar15 Feb 2023 10:25The issue with loosening MALM screws under heavy load is often due to several factors.
Firstly, many of these pieces of furniture are made from particleboard or MDF panels, which do not offer the same strength and screw-holding capacity as solid wood. Under dynamic or cyclic loading, the material around the screw can easily give way.
This is the critical point. Under heavy load, vibrations or movements often occur that cause the fastener to "work." As a result, the joint gradually weakens, and the screw loses its preload.
As a countermeasure, using thread-locking compounds or special locking nuts often helps prevent self-loosening.
Firstly, many of these pieces of furniture are made from particleboard or MDF panels, which do not offer the same strength and screw-holding capacity as solid wood. Under dynamic or cyclic loading, the material around the screw can easily give way.
GLATAU9 schrieb:
that the screws loosen under dynamic load
This is the critical point. Under heavy load, vibrations or movements often occur that cause the fastener to "work." As a result, the joint gradually weakens, and the screw loses its preload.
As a countermeasure, using thread-locking compounds or special locking nuts often helps prevent self-loosening.
narDietmar schrieb:
Many pieces of furniture are made with particleboard or MDF panels, which do not provide the same holding strength as solid wood.Exactly. Additionally, many MALM models lack proper pre-cut joints or reinforcements at the screw points. Under load, the panel joints move slightly, which can cause loosening.
Often, tightening the screws with the correct torque helps, but not too tightly. Over-tightening can damage the material and reduce its holding capacity.
I would like to elaborate on this topic to provide a comprehensive overview.
MALM furniture often uses a combination of particleboard and MDF, which are coated with melamine or foil finishes. While these panels are cost-effective, they have limited tensile and compressive strength. When screws are driven into such materials, the threads often do not grip well in the core of the material but rely mainly on the clamping force.
Under dynamic loads – for example, when leaning on a table or bumping into a chest of drawers – secondary damage can occur. The following factors influence the loosening of screws:
1. Micro-movements between the screw and the wood-based panel caused by material deformation.
2. Creep and relaxation of the wood composite: the material slowly "creeps" around the screw.
3. Vibrations that apply opposing torque to the screws, gradually loosening them.
4. Lack or absence of screw locking mechanisms (e.g., adhesives, locking washers).
Additionally, the factor of correct tightening torque is crucial. If the torque applied is insufficient, the thread loosens more easily; if overtightened, fiber damage occurs, which in turn reduces holding strength.
Mechanical reinforcement (such as metal inserts) can help address this issue.
Are there any detailed specifications regarding the type of screw and connection used? For example, wood screws, self-tapping screws (Spax), or metal threaded inserts? This information could help pinpoint the cause more precisely.
MALM furniture often uses a combination of particleboard and MDF, which are coated with melamine or foil finishes. While these panels are cost-effective, they have limited tensile and compressive strength. When screws are driven into such materials, the threads often do not grip well in the core of the material but rely mainly on the clamping force.
Under dynamic loads – for example, when leaning on a table or bumping into a chest of drawers – secondary damage can occur. The following factors influence the loosening of screws:
1. Micro-movements between the screw and the wood-based panel caused by material deformation.
2. Creep and relaxation of the wood composite: the material slowly "creeps" around the screw.
3. Vibrations that apply opposing torque to the screws, gradually loosening them.
4. Lack or absence of screw locking mechanisms (e.g., adhesives, locking washers).
Additionally, the factor of correct tightening torque is crucial. If the torque applied is insufficient, the thread loosens more easily; if overtightened, fiber damage occurs, which in turn reduces holding strength.
Mechanical reinforcement (such as metal inserts) can help address this issue.
Are there any detailed specifications regarding the type of screw and connection used? For example, wood screws, self-tapping screws (Spax), or metal threaded inserts? This information could help pinpoint the cause more precisely.
Thank you in advance for the initial explanations.
In the case of the MALM dressers I have, mainly metal wood screws with large heads are used, often accompanied by a plastic or metal press-in nut on the back. The panel is standard particleboard.
The screws are tightened by hand without a torque tool, and I’m not sure if this might already cause issues.
My assumption that the combination of material and load is the problem seems likely. Now I’m interested to know if there are easy ways to prevent loosening, for example with thread locking or other mechanisms?
Maybe someone has practical recommendations?
Gafiel schrieb:
Are there more detailed information about the type of screws and connection method used? For example, wood screws, Spax screws, or metal threaded inserts?
In the case of the MALM dressers I have, mainly metal wood screws with large heads are used, often accompanied by a plastic or metal press-in nut on the back. The panel is standard particleboard.
The screws are tightened by hand without a torque tool, and I’m not sure if this might already cause issues.
My assumption that the combination of material and load is the problem seems likely. Now I’m interested to know if there are easy ways to prevent loosening, for example with thread locking or other mechanisms?
Maybe someone has practical recommendations?
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