Specifications

Plain Test Tube · Specifications

The following are standard size options. Custom sizes are available upon request.

Size (OD×Length mm)	Approx. Wall Thickness (mm)	Packaging (pcs/case)	Material	Typical Application
10×75	0.8–1.0	2000	Borosilicate 3.3	Micro-scale
10×100	0.8–1.0	2000	Borosilicate 3.3	Micro-scale
12×75	0.9–1.1	2000	Borosilicate 3.3	General
12×100	0.9–1.1	2000	Borosilicate 3.3	General
13×100	1.0–1.2	2000	Borosilicate 3.3	General
13×130	1.0–1.2	2000	Borosilicate 3.3	General
15×100	1.0–1.2	1000	Borosilicate 3.3	General
15×150	1.0–1.2	1000	Borosilicate 3.3	General
16×125	1.0–1.2	1000	Borosilicate 3.3	General (most common)
16×150	1.0–1.2	1000	Borosilicate 3.3	General
16×160	1.0–1.2	1000	Borosilicate 3.3	General
18×150	1.1–1.3	600	Borosilicate 3.3	General
18×180	1.1–1.3	600	Borosilicate 3.3	General
20×150	1.2–1.4	400	Borosilicate 3.3	Larger volume
20×200	1.2–1.4	400	Borosilicate 3.3	Larger volume
21×150	1.2–1.4	400	Borosilicate 3.3	Larger volume
21×180	1.2–1.4	400	Borosilicate 3.3	Larger volume
21×200	1.2–1.4	400	Borosilicate 3.3	Larger volume
25×150	1.3–1.5	300	Borosilicate 3.3	Large volume
25×180	1.3–1.5	300	Borosilicate 3.3	Large volume
25×200	1.3–1.5	200	Borosilicate 3.3	Large volume
30×200	1.5–1.8	200	Borosilicate 3.3	Large volume
41×225	1.8–2.0	200	Borosilicate 3.3	Extra large volume

* Dimensions are nominal values. Actual dimensions may vary slightly.
* Custom sizes and special specifications available upon request. Bulk pricing available.
* Plain rim — compatible with rubber stoppers, cotton plugs, and silicone closures.

Size Selection Guide: Micro-scale (< 5mL) → 10×75mm ~ 13×100mm; General (5–15mL) → 15×150mm ~ 18×180mm (16×125mm is the most common); Larger volume (15–30mL) → 20×200mm ~ 25×200mm; Extra large (> 30mL) → 30×200mm ~ 41×225mm.

Product Description

Plain test tubes are the most basic, versatile, and frequently used labware in any laboratory. Manufactured from high-quality borosilicate glass 3.3, these tubes feature a clean, cut plain rim, uniform wall thickness, high clarity, and excellent heat and chemical resistance. Suitable for sample storage, reaction vessels, heating experiments, and reagent dispensing. As the most fundamental tube type, plain test tubes serve as the base version for graduated tubes, stoppered tubes, and other specialized tube varieties.

Key Features

Borosilicate Glass 3.3: ISO 3585 compliant · Low thermal expansion · Thermal shock resistance up to 280°C · Resistant to acids and alkalis
Plain Rim: Clean-cut, flat rim — suitable for rubber stoppers, cotton plugs, and silicone closures
Uniform Wall Thickness: Even heat distribution — reduces thermal stress and breakage risk
High Clarity: High-purity glass enables clear observation of samples, color changes, and precipitation
Autoclavable: 121°C / 15 psi / 20 minutes steam sterilization
Chemically Resistant: Compatible with acids, alkalis, salt solutions, and common organic solvents
Comprehensive Range: Over 20 sizes from 10×75mm to 41×225mm

Value Proposition: Plain test tubes are the most economical, practical, and versatile basic labware. One tube = Sample container + Reaction vessel + Heating tube. With reliable quality and comprehensive sizing, they meet the daily needs of any laboratory — an essential consumable for every lab.

Quality Assurance

Each plain test tube undergoes rigorous dimensional inspection, wall thickness uniformity testing, and visual inspection. Our products meet laboratory glassware quality standards.

Note: Plain test tubes are basic tubes — no graduations, no stopper. For graduated functions, choose Graduated Test Tubes; for sealed storage, choose Stoppered Test Tubes; for both, choose Graduated Stoppered Test Tubes.

Applications

Typical Application Areas

Education

Basic laboratory skills training, sample observation in chemistry and biology courses

Routine Chemical Analysis

Reagent preparation, sample dissolution, heating reactions, precipitation experiments

Biological Experiments

Culture preparation, sample temporary storage, pre-centrifugation sample transfer

Pharmaceutical QC

Sample vessels in daily testing, solution preparation

Environmental & Food Testing

Water sample and food extract temporary storage and processing

Research

General-purpose vessels in exploratory experiments

Comparison with Other Tube Types

Plain vs Rolled-Rim Plain rim suits stoppers; rolled rim offers enhanced rim strength
Plain vs Graduated Plain tubes are more economical; graduated tubes provide volume estimation
Plain vs Stoppered Plain tubes require separate closures; stoppered tubes include ground glass stoppers

Tip: Plain test tubes are the most economical general-purpose laboratory vessels. For applications requiring precise volume or sealed storage, choose graduated or stoppered tubes.

Plain Test Tube Operation Guide

03

Preparation Before Use

Inspect for cracks, chips, or rim damage
Wash with mild detergent and soft brush — rinse 3 times with distilled water
Autoclave at 121°C / 15 psi / 20 minutes
Dry at 60°C or air dry inverted before use

04

Routine Operation

Filling: Do not exceed 1/2 of tube capacity (1/3 when heating)
Heating: Use a tube holder at 1/3 from the rim — tilt at 45° — heat evenly to avoid localized overheating
Mixing: Use a glass stirring rod or gently flick the tube wall
Closure: Use rubber stoppers, cotton plugs, or silicone stoppers as needed

05

Heating Precautions

Never point the tube opening toward anyone when heating liquids
When heating solids, tilt the tube slightly downward to prevent condensate from cracking the bottom
Do not quench hot tubes with cold water — thermal shock may cause breakage

06

Cleaning & Maintenance

Clean immediately after use to prevent residue adhesion
Routine cleaning: Mild detergent + soft brush — rinse 3 times with distilled water
Stubborn residues: Soak in dilute nitric acid or specialized cleaning solution
Air dry inverted or place in oven at 60°C
Store upright in dedicated test tube racks

Care & Notes

Show care & notes

Safety Precautions

Inspect for cracks or scratches before use — damaged tubes may break when heated
When handling flammable, explosive, or toxic samples, work in a fume hood
Wear protective gloves and goggles when handling strong acids and alkalis
Heated tubes are extremely hot — allow to cool before handling

Do not

Never place plain test tubes directly on hot plates or open flames — use a tube holder with a Bunsen burner