Where does the timber grain run across a narrow width or short distance, causing a weakness?

Where does the timber grain run across a narrow width or short distance, causing a weakness?

• A. Short grain (timber)
• B. Long grain
• C. End grain
• D. Interlocked grain

Answer: (A)

The main idea is how grain direction affects strength. Timber is strongest when forces run along the grain because the long fibers carry the load effectively. When the grain runs across a narrow width or short distance, the fibers are arranged perpendicular to the length of the piece, so there’s less continuous fiber to resist the load. This makes the timber prone to splitting or tearing across the grain, producing a weakness. That orientation is called short grain. Long grain runs along the length, so it’s typically stronger for loads in that direction. End grain shows the ends of fibers and behaves differently, often absorbing more moisture and showing end-grain wear. Interlocked grain, where fibers twist between layers, can cause irregular splitting but isn’t specifically describing the across-the-width weakness described.

The main idea is how grain direction affects strength. Timber is strongest when forces run along the grain because the long fibers carry the load effectively. When the grain runs across a narrow width or short distance, the fibers are arranged perpendicular to the length of the piece, so there’s less continuous fiber to resist the load. This makes the timber prone to splitting or tearing across the grain, producing a weakness. That orientation is called short grain.

Long grain runs along the length, so it’s typically stronger for loads in that direction. End grain shows the ends of fibers and behaves differently, often absorbing more moisture and showing end-grain wear. Interlocked grain, where fibers twist between layers, can cause irregular splitting but isn’t specifically describing the across-the-width weakness described.