Thermos flask specifications come down to four lines: the steel grade, the wall construction, the capacity in ml, and the lid type. The rest of the sheet refines that choice rather than making it.
Reading them correctly separates a corporate gift that stays in a drawer from one carried daily. This guide explains each line on a stainless steel thermos flask in Malaysia; for the whole category see our corporate drinkware guide.
Steel grade: what 304 and 316 mean on a thermos flask
304 stainless steel is 18/8 chromium-nickel austenitic steel, the standard food-grade steel in most flasks. 316 stainless steel adds molybdenum, improving resistance to chlorides and acidic drinks such as tea, coffee and isotonic drinks. For a corporate gift, 304 is the default and 316 the premium tier.
One detail catches out most buyers: a spec sheet often states the grade for the inner liner only, and some flasks mix grades — 316 where the drink touches steel, 304 outside. If a sheet says only "stainless steel", ask which layer.
OASIS Glide Double Layer Travel Tumbler - 350ml
The OASIS Glide travel tumbler is the clearest mixed-grade example: 304 stainless steel outer and 316 inner, so the drink only meets the higher-spec steel. The body measures 185 × 76 mm, holds 350ml (12oz), weighs 302g empty and sits in a car cup holder. The tumbler is leak proof, closes with a clear-topped screw cap whose underside carries a sealing disc, and the mouth is fully steel-lined. Colours are Khaki and Dark Grey, each in a white paper box, and the body takes silk screen or UV DTF decoration.
IRIS 316 Stainless Steel Thermos Flask - 280ml
The IRIS 316 thermos flask specifies SUS 316 stainless steel throughout, with the liner base stamped 316 so the grade is visible. It is double layer insulated and rated to keep drinks warm and cold up to 12 hours. The slim body measures 173 × 56 mm, holds 280ml (9.5oz), weighs 171g and fits in one hand. The pearl body paint has a silky, smooth finishing in Pearl Black, Pearl Navy Blue, Pearl White and Pearl Green, each packed in a colour paper box, taking UV print, laser engraving or silkscreen.
Double wall and vacuum insulation: what the spec sheet is really claiming
A single wall bottle has one steel skin and sweats with cold drinks. A double wall bottle adds a second skin with a gap that slows heat transfer. A double wall vacuum flask evacuates that gap, leaving the lid and neck as the heat path.
A claim such as "keeps warm and cold up to 12 hours" is measured with the flask full and the lid closed throughout, so a half-filled flask opened all day will not match it. In Malaysia's climate a vacuum flask is used at least as often for cold drinks as for hot, and the food grade PP lid or inner cap is the part of the seal the vacuum wall cannot provide. See our round-up of premium tumblers and thermos flasks.
Capacity: matching ml to the recipient
The bands in our range are 280ml, 320ml, 350ml, 500ml, 720ml and 1000ml. 280ml to 350ml suits a handbag, a desk or an executive gift. 500ml is the standard corporate gift size, safest for a mixed staff list. 650ml and above suits outdoor and site teams.
LANTERN Thermos Stainless Steel Bottle - 1000ml
The LANTERN thermos bottle shows the large end of the range: a 304 stainless steel inner, vacuum sealed and double wall insulated, described as retaining drink temperature longer rather than quoting an hour figure. It measures 230 × 90 mm, holds 1000ml and weighs 448g empty. The wide-mouth screw cap carries a flexible loop on top and a silicone sealing ring inside, and a removable non-slip silicone base cover protects desks. Colours are Beige, Black, Green, Grey and Blue in rubber-coated and powder-coated finishes, in a printed white paper box.
Lid types and what they change in daily use
A screw cap with a seal ring is the most secure and easiest to clean, but needs two hands. A one-press flip lid with a slide safety lock opens with a thumb and stays shut in transit. A dual-lid system ships with two interchangeable tops, a lid that doubles as a cup suits shared drinks, and a magnetic-ring lid adds a carry ring and phone holder to a standard screw lid.
Lock Tech Stainless Steel Vacuum Thermos Flask - 500ml
The Lock Tech vacuum thermos flask combines 304 stainless steel with a BPA-free food grade PP lid. The hinged flip-top has a press button for single-press auto-open and a small red slide that locks and releases in one movement, so the lid cannot open inside a bag. A moulded drinking spout sits inside the lid, which is vacuum seal-tight and anti-leak; the flask is rated up to 12 hours. It measures 238 × 70 mm, holds 500ml (17oz) and weighs 380g, in Black, Gold, White, Pearl White and Pearl Black.
GOLD Dual Lid 316 S.Steel Bottle with Straw Handle - 500ml
The GOLD dual lid bottle ships with a spout lid and a straw lid, covering both drinking styles. The inner is 316 stainless steel built as one piece with no internal joins, and 316 offers vastly superior corrosion resistance to chlorides and acids such as tea and coffee. A ring-shaped silicone carry handle sits on the lid, a silicone sealing ring inside it, and the wide opening makes cleaning and ice loading easy. The squat body measures 190 × 75 mm, holds 500ml, weighs 315g and fits a car cup holder.
The other lines on the thermos flask specification sheet
Pearl paint, powder coat, rubber coat and matt each take decoration differently, as set out in how to choose a logo printing method for thermos flasks. Giftstalk runs UV print, laser engraving and UV DTF in-house in Selangor, so the schedule stays in our hands and a mid-run artwork change is handled the same day; silk screen, pad print and hot stamping are also available.
| Spec line | What to check |
|---|---|
| Product dimension | Height × diameter; diameter decides car cup-holder fit. |
| Weight | Always empty weight; heavier usually means a thicker wall or a larger capacity. |
| Base | Non-slip silicone or EVA; check if removable. |
| Finish | The finish, not the steel, decides which method prints cleanly. |
| Packaging | Each flask comes in its own box, plain white or printed colour. |
| Print type | The methods allowed on that body; silk screen only rules out engraving. |
A quick checklist before you approve a flask for a corporate order
- Confirm which layer the steel grade applies to.
- Confirm the construction is double wall vacuum, not just double wall.
- Match the ml figure to how the recipient drinks.
- Check the lid mechanism and diameter against the real use case.
- Approve artwork early — production runs 5 to 14 working days after artwork confirmation and payment received, from a small batch to a bulk order.
FAQ
Is 316 stainless steel better than 304 for a thermos flask?
316 stainless steel resists chlorides and acidic drinks better than 304 because it contains molybdenum, the stronger choice for recipients who brew coffee or tea daily. 304 remains the standard food-grade steel, and many flasks combine both.
How long does a vacuum flask actually keep drinks cold?
A rating such as "up to 12 hours" is measured with the flask full and the lid closed for the whole test, so real performance depends on how often the lid is opened. A flask left half filled or in a hot car holds temperature for less.
What capacity thermos flask is best for a corporate gift?
500ml is the safest capacity for a general corporate gift because it suits desk use, commuting and light outdoor use without being awkward to carry. Choose 280ml to 350ml for executive gifts, and 1000ml for outdoor and site teams.
The rest of the sheet is then quick to check. Browse our full drinkware range, then contact our team for a quote.
