Trim off parenthesized text from columns that have it?

I have an NVARCHAR(80) column. Some column values end with a space, followed by a number within parentheses. (As shown below.)

Is there a SQL-Server syntax to remove the space, parentheses, and number from values that have them, but leave all other values unchanged?

For example, "SANDFRAC4070 (1441316)" would become "SANDFRAC4070", and "SAND FRACING 30 50 MESH" would be unchanged.

Sample Data

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SAND FRACING 100 MESH (1441317)
SAND FRACING 100 MESH (1441317)
SANDFRAC4070 (1441316)
SANDFRAC4070 (1441316)
SANDFRAC4070 (1441316)
SANDFRAC4070 (1441316)
SANDFRAC4070 (1441316)
SANDFRAC4070 (1441316)
SANDFRAC4070 (1441316)
SANDFRAC4070 (1441316)
SANDFRAC4070 (1441316)
SANDFRAC4070 (1441316)
SANDFRAC4070 (1441316)
SANDFRAC4070 (1441316)
SANDFRAC4070 (1441316)
SANDFRAC3050MES
SANDFRAC3050MES
SANDFRAC3050MES
SANDFRAC3050MES
SANDFRAC4070MES
SANDFRAC4070MES
SANDFRAC4070MES
SANDFRAC4070MES
SANDFRAC4070MES
SANDFRAC4070MES
SANDFRAC4070MES
SAND FRACING 30 50 MESH
SAND FRACING 30 50 MESH

One option is charindex() with a "Fail-Safe"

Example

Declare @YourTable Table ([SomeCol] varchar(50))  Insert Into @YourTable Values 
 ('SANDFRAC4070 (1441316)')
,('SANDFRAC3050MES')
 
Select * 
      ,left(SomeCol,charindex(' (',SomeCol+' (')-1)
 From @YourTable

Results

SomeCol             	 (No column name)
SANDFRAC4070 (1441316)	 SANDFRAC4070
SANDFRAC3050MES     	 SANDFRAC3050MES

Just in case the comment in which I posted this dbfiddle disappears I'll move it to an answer:

declare @Samples as Table ( Sample VarChar(80) );
insert into @Samples ( Sample ) values
  ( 'SAND FRACING 100 MESH (1441317)' ),
  ( 'SANDFRAC4070 (1441316)' ),
  ( 'SANDFRAC4070(1441316)' ),
  ( 'SANDFRAC3050MES' ),
  ( 'SAND FRACING 30 50 MESH' ),
  ( 'SAND FRACING (30) 50 MESH' ),
  ( 'SAND FRACING (30) (50) MESH' ),
  ( 'SANDFRAC4070 (1441)(316)' ),
  ( 'SANDFRAC4070 (1441) (316)' ),
  ( 'SANDWICH CHICKEN (NO ONION)' ),
  ( 'SAND ()' ),
  ( 'SAND (0)' ),
  ( 'SAND (-0)' ),
  ( 'SAND (6.022E+23)' ),
  ( 'SAND (e)' ),
  ( '' ),
  ( NULL );

with
  Step1 as (
    select Sample,
      -- Find the last open parenthesis by searching backwards from the end of the string.
      Len( Sample ) - CharIndex( '( ', Reverse( Sample ) ) as LastOpenParen
      from @Samples ),
  Step2 as (
    select Sample, LastOpenParen,
      case
        -- If there was no open parenthesis, or no string, then we're done.
        when LastOpenParen = Len( Sample ) or LastOpenParen is NULL then NULL
        -- The target substring runs from the last open parenthesis to the end of the string.
        else Substring( Sample, LastOpenParen + 1, 80 ) end as Target
      from Step1 )
  select Sample, Len( Sample ) as Length, LastOpenParen,
    case
      -- Nothing interesting.
      when Target is NULL then Sample
      -- A string in parentheses, but including a non-digit character.
      when Target like '(%[^0-9]%)' then Sample
      -- A string in parentheses with at least one digit and no non-digits.
      when Target like '(%[0-9]%)' then RTrim( Left( Sample, LastOpenParen ) )
      -- Empty parenteses.
      else Sample end as CorrectedSample
    from Step2;

Note that not every value that might be considered a number is handled as the OP was rather vague about decimal, negative, scientific, ... values.