PYREX Vista 50 mL Class B
- 50 mL capacity
- Class B grade, twice the Class A tolerance
- Pack of 6 flasks
- No. 50 polyethylene snap-caps fit the neck
- Sharp, permanent graduation line, blue block lettering
Updated 2 days ago · Based on the Amazon listing and published specifications, not hands-on testing.
Class B volumetric flasks for work that does not need the tightest accuracy. They suit general lab prep, and the listing gives no dimensions or weight.
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ASIN: B0GSS8N2QNModel: 70581-50Category: Volumetric Flasks
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Overview
PYREX Vista flasks in the Class B grade are made for users who do not need the accuracy of Class A. The necks are heavy duty and shaped for polyethylene snap-caps. Large blue letters and a permanent graduation line make them easy to read.
A looser tolerance is the reason these exist: routine prep work does not always need the highest grade. The limit is the same loosened accuracy, and the listing leaves out size and weight.
Who it's for
Teaching labs and general prep work where approximate volumes are acceptable will find the looser grade adequate. Analysts making calibration standards should use Class A flasks.
Pros and cons
- Class B grade for routine work
- Heavy duty necks
- Snap-cap compatible neck
- Permanent graduation line
- Looser accuracy than Class A
- Caps not listed as included
- Dimensions not listed
- Weight not listed
Performance notes
Capacity tolerance in this grade is twice that of Class A, so the final volume can vary more from flask to flask. A single graduation line on the neck sets the fill point. Polyethylene snap-caps close the neck for short-term storage.
Specifications
| Brand | Pyrex |
|---|---|
| Model | 70581-50 |
| Capacity | 50 mL |
| Neck | Tooled for No. 50 polyethylene snap-caps |
| Pack quantity | 6 flasks |
| Specification met | Class B |
| Part number | 70581-50 |
Frequently asked questions
How do I care for PYREX Vista Class B flasks?
The listing gives no care instructions. Handle them as laboratory glassware, rinse with the cleaning method your lab uses, and avoid dropping them.
Do the PYREX 70581-50 flasks come with caps?
The title says polyethylene snap-cap, but the listing does not clearly say the caps are included. Necks are tooled for No. 50 snap-caps.
How does Class B differ from Class A?
Capacity tolerances are twice those specified for Class A volumetric ware.
Are these flasks Class A?
No. They are Class B.