Trusted by world-class resorts and professionals — now available for your home.

Smooth Fit Rectangular Tube Plugs

Smooth fit rectangular tube plugs are designed for wide rectangular tubing where standard ribbed plugs may not seat evenly. PA (polyamide) construction provides a flush, precise insertion body that slides into wide profiles without the binding or gapping that PE ribs can cause on high-aspect-ratio tubes. 4 sizes: 15 × 80, 20 × 80, 20 × 100, and 25 × 100 mm. Wall thickness 1 to 2 mm (15 × 80 is 1.5 to 2 mm). PA rectangular tube plugs for wide commercial furniture bases, display fixtures, and industrial frames. Black, grey, and white. Sold in multiples of 4.

$1.23$1.97

4 = 1 chair · 8 = 2 chairs · 24 = 6 chairs

Item Number Not Available Product Type Features ,

Not sure what size? See the size chart ↓

📦 Sold in packs of 4 — quantity adjustable at checkout

Overview

Smooth Fit Rectangular Tube Plugs

Standard rectangular tube plugs use PE ribs that compress during insertion. That works perfectly on most sizes. But on wide, shallow rectangular tubing (80 to 100 mm on the long side), the aspect ratio creates a problem: ribs that compress evenly on a 30 × 50 mm tube do not compress evenly on a 20 × 100 mm tube. The wide wall flexes differently than the narrow wall, leading to gaps, binding, or uneven seating. Smooth fit rectangular tube plugs solve this with a different material and a different insertion geometry.

PA (polyamide) construction instead of PE. A flush, precise insertion body instead of flexible ribs. The PA body slides into wide profiles with even contact across the entire cross-section. Smooth fit rectangular tube plugs are PA rectangular tube plugs engineered for the 4 specific wide-profile sizes that standard ribbed plugs cannot handle cleanly: 15 × 80, 20 × 80, 20 × 100, and 25 × 100 mm. Black, grey, and white. Sold in multiples of 4.

Available Sizes: 4 Smooth Fit Rectangular Tube Plugs

Smooth fit rectangular tube plugs are available in 4 sizes, all featuring the wide aspect ratio that defines this product. The right smooth fit plug matches your tube’s width, length, and wall thickness.

15 × 80 mm

Wall: 1.5 to 2 mm. The narrowest width with 80 mm length. For slim, wide structural members. Black only.

20 × 80 mm

Wall: 1 to 2 mm. Standard width for commercial table bases and fixture frames. The most popular smooth fit size. Black, grey, and white.

20 × 100 mm

Wall: 1 to 2 mm. Extra-wide profile for heavy-duty table bases and industrial frames. Black and grey.

25 × 100 mm

Wall: 1 to 2 mm. The widest and deepest smooth fit profile. For the heaviest commercial and industrial structural members. Black and grey.

For standard rectangular profiles up to 60 × 120 mm that do not require smooth fit, use rectangular tube plugs (32 sizes, PE with ribs). For square profiles, use square tube plugs. For custom smooth fit sizes, contact Business Solutions.

How to Measure Your Tube for Smooth Fit Rectangular Tube Plugs

Same three measurements as standard rectangular tube plugs: width (short side), length (long side), and wall thickness. Smooth fit rectangular tube plugs require one of the 4 specific size and wall combinations listed above. If your tube does not match, check standard rectangular tube plugs for a compatible size.

Step 1. Measure both outside dimensions

Use calipers or a ruler across each side of the rectangular tube, outside edge to outside edge. Record the short side (width) and the long side (length). Smooth fit rectangular tube plugs are available for widths of 15, 20, and 25 mm with lengths of 80 and 100 mm.

Step 2. Measure the wall thickness

Use calipers at the tube end. Most smooth fit sizes require 1 to 2 mm wall. The 15 × 80 size requires 1.5 to 2 mm. The smooth PA body needs precise dimensional contact, so wall thickness accuracy matters more than with standard ribbed plugs.

Step 3. Confirm all three values

Width, length, and wall thickness must all match. The smooth fit body has tighter dimensional tolerances than ribbed PE plugs because it relies on surface contact rather than rib compression for its grip.

When to choose smooth fit: if your tube is 15 × 80, 20 × 80, 20 × 100, or 25 × 100 mm, smooth fit is the correct product. These sizes are not available in the standard ribbed range. If your tube is a different rectangular dimension, use standard rectangular tube plugs.

How to Install Smooth Fit Rectangular Tube Plugs

Simpler than ribbed plugs. The smooth PA body slides into the tube with even contact across all surfaces. No ribs to compress means less insertion resistance and more even seating. Orientation still matters: match width to width and length to length.

What you need
  • The correct smooth fit rectangular tube plug matched to your width, length, and wall thickness
  • A rubber mallet (optional, usually not needed)
  • Clean, dry tube ends free of burrs, weld spatter, paint buildup, or debris
Installation steps
  1. Inspect the tube end. Clean the inside surface. Any debris, paint drips, or weld spatter on the inner walls will prevent the smooth body from seating properly. This step is more critical for smooth fit than for ribbed plugs because the grip depends on clean surface contact.
  2. Align the smooth fit rectangular tube plug with the tube opening. Match width to width and length to length. The plug will not fit if rotated 90°.
  3. Slide the plug into the tube by hand. The PA body enters evenly across the full cross-section. Push until the head sits flush with the tube edge.
  4. If the plug does not slide in easily, check for debris, dimensional mismatch, or paint buildup inside the tube. Do not force it. A smooth fit plug that does not slide in cleanly is likely the wrong size or the tube is obstructed.
Removal: pry gently from one edge with a flat-head screwdriver. The PA body is more rigid than PE but still flexes enough for removal. Smooth fit rectangular tube plugs can be reinstalled if undamaged.

What Smooth Fit Rectangular Tube Plugs Solve

The specific problem of wide-aspect-ratio rectangular tubing that standard ribbed plugs cannot handle evenly. The National Wood Flooring Association (NWFA) recommends protective measures on all furniture legs, and smooth fit rectangular tube plugs provide that protection on the wide structural tubing that standard plugs miss.

Even seating on wide profiles

The primary advantage. On a 20 × 100 mm tube, the long wall is 5 times wider than the short wall. Standard PE ribs compress differently on each wall, creating uneven seating: the plug may gap on the long wall while binding on the short wall, or vice versa. Smooth fit rectangular tube plugs eliminate this problem with a flush PA body that contacts all four walls evenly. Wide profile tube plugs that seat correctly the first time. Rectangular tube plugs wide enough for commercial and industrial structural members.

Floor protection on wide structural members

Wide rectangular tubing is often used for table bases and fixture frames where the tube end contacts the floor with a broad footprint. The smooth PA head covers the full rectangular cross-section. Unlike leaving metal edges unprotected, the PA surface prevents scratching. PA has a lower coefficient of friction than PE, so smooth fit plugs actually glide more quietly on hard floors. For additional scratch protection, apply a rectangular self-adhesive furniture pad to the plug head.

Tube sealing

Same complete seal as ribbed plugs. The smooth PA body fills the tube opening and prevents moisture, debris, dust, and insects from entering. On wide structural tubing that sits at floor level, the large tube opening is especially vulnerable to water, cleaning solution runoff, and tracked-in debris. Smooth fit rectangular tube plugs seal the full opening.

PA material advantages

PA (polyamide) brings properties that PE does not. Higher tensile strength: the body maintains shape across the full 80 to 100 mm width without flexing. Better chemical resistance: tolerates industrial cleaning agents, solvents, and commercial kitchen chemicals. Wider temperature range: stable from -40 °C to 85 °C compared to PE’s -25 °C to 65 °C. Lower friction coefficient: smoother floor contact. These are the smooth fit plugs for furniture and fixtures in demanding commercial and industrial environments.

Materials and Construction

PA (polyamide) throughout. This is the key difference from every other tube plug in the range, which uses PE. Smooth fit rectangular tube plugs are molded from a single piece of PA with no joints, seams, or separate components.

PA (Polyamide) Body Smooth insertion

The entire plug, head and body, is PA. The body slides into the tube with a flush profile that relies on precise dimensional contact rather than rib compression. PA provides the rigidity needed to maintain shape across wide profiles without flexing during insertion or under load.

  • Extreme toughness and high tensile strength
  • High flexibility and impact strength
  • Excellent chemical resistance (acids, alkalis, solvents)
  • Low coefficient of friction: smooth insertion and quiet floor contact
  • Temperature range: -40 °C to 85 °C
  • Recyclable
  • Black, grey, and white (availability varies by size)
Flush Insertion Profile Grip mechanism

Instead of flexible ribs, smooth fit rectangular tube plugs use a precisely dimensioned body that grips through surface contact. The PA body is machined to tight tolerances so it slides in with consistent friction across all four walls. On wide profiles, this even contact is what makes the difference: every square millimeter of the body contributes to the grip rather than relying on discrete rib points.

  • Flush profile: no ribs, no compression points
  • Even contact across all four interior walls simultaneously
  • Precision-molded to tight dimensional tolerances
  • Grip strength from full-surface friction, not point compression
  • No adhesive required for standard applications

Smooth Fit Rectangular Tube Plugs vs. Other Options

If your furniture has wide rectangular tubing in the 80 to 100 mm length range, here is how smooth fit rectangular tube plugs compare to the alternatives.

vs. Standard Ribbed Rectangular Tube Plugs

Standard rectangular tube plugs use PE with flexible ribs. On profiles up to about 60 × 120 mm, they work well. On wide, shallow profiles like 20 × 100 mm, the ribs compress unevenly. Smooth fit rectangular tube plugs solve this with PA and flush geometry. Use standard ribbed for most rectangular sizes. Use smooth fit for the 4 specific wide-profile sizes.

vs. Rectangular Tube Plugs with Pad

Rectangular tube plugs with pad have integrated PA6 floor protection but are available in different sizes (13.8 × 27.5 and 20 × 30 mm). No overlap with smooth fit sizes. The two products serve different tube dimensions.

vs. Leaving Wide Tubes Open

An open 20 × 100 mm tube presents 240 mm of exposed sharp metal edge at the tube end. That is more than twice the exposed edge of a typical chair leg tube. Smooth fit rectangular tube plugs seal the entire opening with a single press-fit plug.

vs. Welding a Plate

Welding a plate over a wide tube end is more common at these sizes than on smaller tubes, but it requires equipment, refinishing, and is not removable. Smooth fit rectangular tube plugs push in by hand, are removable, and preserve the tube finish.

Where Smooth Fit Rectangular Tube Plugs Work Best

Smooth fit rectangular tube plugs are designed exclusively for wide rectangular tubing where standard ribbed plugs cannot seat evenly. The 4 available sizes cover the most common wide-profile specifications in commercial and industrial furniture.

Ideal applications
  • Commercial table bases with wide rectangular tubing (conference tables, dining tables, training tables)
  • Display fixture bases and retail shelving supports
  • Industrial workbench frames and heavy-duty equipment bases
  • Architectural structural elements with exposed wide rectangular profiles
  • Any 15 × 80, 20 × 80, 20 × 100, or 25 × 100 mm hollow rectangular tube end
Not ideal for

All Tube Plug Shapes

Match the plug shape to your tube shape. Every shape uses the same press-fit concept with material and geometry optimized for the profile.

Round

26+ sizes, Ø 10 to 80 mm. 7 head styles. PE.

Square

16 sizes, 13 × 13 to 100 × 100 mm. PE.

Rectangular (Standard)

32 sizes, 10 × 30 to 60 × 120 mm. PE ribs.

Rectangular (Smooth Fit) ← You are here.

4 wide-profile sizes, 80 to 100 mm. PA.

Oval

Oval cross-section profiles.

Ellipse

Elliptical cross-section profiles.

Where People Use Smooth Fit Rectangular Tube Plugs

Anywhere wide rectangular tubing has open ends that need finishing, sealing, and floor protection with even seating across the full profile width.

Commercial furniture

Conference tables, training tables, dining tables, and desks with wide rectangular tube bases. The 20 × 80 and 20 × 100 mm sizes cover the most common commercial table base tubing. Smooth fit rectangular tube plugs seal and finish these wide profiles cleanly where ribbed plugs would gap. Available in bulk for manufacturing runs and facility fit-outs. For commercial pricing, visit Business Solutions.

Industrial and architectural

Heavy-duty workbenches, industrial equipment frames, retail fixture bases, and architectural structural elements. The 25 × 100 mm size handles the heaviest wide-profile tubing. In industrial environments, the PA material’s superior chemical resistance and wider temperature range make smooth fit plugs more durable than PE alternatives. For floor-contact bases that also need PA6 scratch protection, pair with rectangular self-adhesive furniture pads. For rough hard floors like textured tile or stamped concrete, furniture slides with ABS surfaces handle the texture better than PA or PE on floor contact. In environments where the furniture must stay in place rather than slide, consider adding anti-slip pads to the plug base after installation.

Maintenance and Inspection

Smooth fit rectangular tube plugs require minimal maintenance. PA is more durable than PE under chemical exposure and temperature variation, so these plugs outlast standard PE plugs in demanding environments. Check periodically that the plug remains seated flush with the tube edge. The smooth body is less likely to work loose under vibration than ribbed plugs because the grip is distributed across the full surface rather than concentrated at rib points. On wide profiles, the large contact area provides a stable, even hold that resists both pull-out and rocking forces.

On commercial furniture that gets moved frequently, inspect every 6 months. On static industrial equipment and fixtures, an annual check is enough. The PA surface does not stain, discolor, or absorb cleaning products or industrial solvents. In commercial kitchens, laboratories, and manufacturing facilities where aggressive cleaning chemicals are used daily, PA holds up where PE would degrade over time. These plugs are sold in multiples of 4, so keeping spares on hand is practical for commercial and industrial environments. If a plug becomes damaged or no longer seats securely, replace it with a new smooth fit plug. The PA body does not crack like PE under repeated stress; instead it maintains its shape until the dimensional tolerance loosens enough to affect grip.

Related Products

Standard ribbed for other sizes

Rectangular Tube Plugs: PE with ribs, 32 sizes from 10 × 30 to 60 × 120 mm. For all rectangular sizes outside the smooth fit range.

Floor protection for rectangular legs

Rectangular Self-Adhesive Furniture Pads: PA6 for scratch protection on hard floors. Apply to the plug head or along the tube base.

Rectangular Self-Adhesive Furniture Glides: PA6 on ABS platform for glide performance.

Specifications

Specification Details
Product Type
Tube Plugs – Inner (Type 2)
Shape
Rectangular Tube
Materials
PA (Polyamide)
Fit Style
Smooth, rib-free compression fit
Floor Compatibility
All hard and soft flooring
Furniture Compatibility
Chairs, benches, industrial frames, carts, trolleys, storage systems
Leg Compatibility
Metal and plastic rectangular tubing
Sizes Available
15 × 80 mm to 25 ×100 mm, fits 1–2 mm wall thickness
Color Options
Black, Grey, White
Installation Type
Press-fit by hand or rubber mallet
Key Benefits
Flush finish, chemical resistance, impact resistance, fast install
Indoor/Outdoor Use
Indoor | Covered Outdoor | Uncovered Outdoor
Recyclable
Yes

Size Chart

Tube Dimensions (L x W) Tube Wall Thickness (T) Head Height (H1) Insert Depth (H)
15 x 80 mm (0.59" x 3.15")
1.5 – 2 mm (0.06" – 0.08")
5 mm (0.19")
14 mm (0.55")
20 x 80 mm (0.79" x 3.15")
1 – 2 mm (0.04" – 0.08")
5 mm (0.19")
14 mm (0.55")
20 x 100 mm (0.79" x 3.94")
1 – 2 mm (0.04" – 0.08")
5 mm (0.19")
14 mm (0.55")
25 x 100 mm (0.98" x 3.94")
1 – 2 mm (0.04" – 0.08")
5 mm (0.19")
14 mm (0.55")

Frequently Asked Questions

What makes smooth fit different from standard rectangular tube plugs?

Standard rectangular tube plugs use PE with flexible ribbed walls that compress during insertion. Smooth fit rectangular tube plugs use PA (polyamide) with a flush-profile body engineered for wide tubes. On profiles 80 to 100 mm long, standard ribs may not compress evenly across the full width, leading to gaps on one axis or binding on the other. The smooth PA body provides more even seating across the entire cross-section.

Is the hold as strong as ribbed plugs?

The hold mechanism is different. Smooth fit rectangular tube plugs rely on precise dimensional matching between the PA body and the tube interior rather than rib compression. The fit is firm and sufficient for all standard furniture applications. For environments with extreme vibration or pull-out force, standard ribbed plugs in a matching size would provide stronger retention.

Why PA instead of PE?

PA (polyamide) has higher tensile strength and rigidity than PE. On wide profiles, the body needs to maintain its shape across 80 to 100 mm without flexing or warping during insertion. PA holds its geometry. PE would flex too much at these widths. PA also handles a wider temperature range and has better chemical resistance than PE.

Can I use standard ribbed rectangular plugs in these sizes instead?

Standard rectangular tube plugs are available up to 60 × 120 mm, but none cover the specific 15 × 80, 20 × 80, 20 × 100, or 25 × 100 dimensions. These sizes are only available as smooth fit. Even if a close standard size existed, the wide aspect ratio would make ribbed insertion uneven.

What types of furniture use 80 to 100 mm wide rectangular tubing?

Commercial table bases, conference table frames, heavy-duty display fixtures, industrial workbenches, retail shelving supports, and architectural structural elements. The wide, shallow profile distributes load across a broad footprint. These are not typical chair legs. They are structural members on larger, heavier furniture and fixtures.

Reviews

Reviews

There are no reviews yet

Only logged in customers who have purchased this product may leave a review.

Overview Specs Size Chart FAQs Reviews