Understanding Different Groove Sizes: What Size Groove Should You Choose?
When refurbishing a staircase, one of the most important details to get right is the groove size in your handrail and baserail. The groove determines which spindles or glass panels will fit, and choosing the wrong size can delay a project or lead to parts not fitting at all, so understanding different groove sizes can be very important.
At Shaw Stairs, we offer several groove sizes to suit glass, metal and timber options in a variety of designs. Each photo below shows an example of what each groove size looks like in our handrails and baserails, so here’s a clear and simple breakdown to help you choose and understand different groove sizes.
8mm Groove – For 8mm Glass Panels
The 8mm groove is designed specifically for 8mm toughened glass.
Perfect if you want:
- a clean, modern look
- lighter-weight glass
- a bright, open hallway
8mm glass is ideal for smaller hallways or for customers wanting a slim profile.
10mm Groove – For 10mm Glass Panels
The 10mm groove is for 10mm toughened glass, giving you a slightly thicker, heavier feel.
Choose 10mm if you want:
- a more solid panel
- a premium finish
- strong durability for busy homes
Many customers choose 10mm for open plan homes where the staircase is a key feature.
13mm Groove – For Black Metal Spindles
The 13mm groove is the standard size for our black metal spindles, including:
If you’re choosing a modern metal spindle staircase, you’ll almost always need a 13mm groove.
25mm Groove – For Chunky Black Metal Spindles
The 25mm groove is used for our chunky black metal spindles, which are much thicker and offer a bold, dramatic look.
A great choice if you want:
- a heavy, contemporary appearance
- strong visual impact
- a feature staircase
These spindles work brilliantly with square newels and modern interiors.
32mm Groove – For 32mm Timber Spindles
32mm timber spindles with a 32mm handrail and baserail are slim and elegant, ideal for:
- period-style staircases
- painted finishes
- homes wanting a more traditional look
These are often seen in older properties wanting to stay true to their original style.
35mm Groove – For 35mm Timber Spindles
35mm is a versatile size and sits between slim and chunky.
Often chosen for:
- modern traditional designs
- subtle upgrades
- customers wanting a balanced, not-too-heavy look
35mm spindles give you a balanced look and a presence without overpowering the staircase. They’re ideal for customers who want something stronger than 32mm but not as bold as 41mm.
41mm Groove – For 41mm Timber Spindles
41mm timber spindles are the classic, traditional size. They offer a strong presence on the staircase and remain one of the most popular choices for timber refurbishments with a 41mm handrail and baserail. Ideal for:
- statement staircases
- oak and hemlock upgrades
- customers who want a solid, timeless look
41mm is the standard in many British homes and works well with both turned and square spindle styles.
Quick Reference Guide
| Groove Size | Product Type | Best For |
|---|---|---|
| 8mm | 8mm glass panels | Light, slim, modern finish |
| 10mm | 10mm glass panels | Premium thickness and durability |
| 13mm | Black metal spindles | Modern, minimalist, decorative metal styles |
| 25mm | Chunky black metal spindles | Bold, contemporary feature staircases |
| 32mm | Timber spindles | Slim traditional look |
| 35mm | Timber spindles | Modern-traditional, balanced style |
| 41mm | Timber spindles | Classic, strong, traditional design |
Final Thoughts
Choosing the right groove size is crucial for a smooth refurbishment, and as you can see understanding different groove sizes is important. Whether you’re installing glass, black metal, chunky metal or traditional timber spindles, Shaw Stairs has handrails and baserails in various designs, timbers and lengths available in our online shop.
If you’re unsure which groove size you currently have, contact us here. We’re always happy to help you get it right the first time.